Under the transitional regulations, you are not excluded from the family class and your father should be able to sponsor you.
A letter from a lawyer stating the regulations should be sufficient for the Visa Officer to give approval!
http://laws.justice.gc.ca/eng/SOR-2002-227/page-1.html see section
Division 8
Non-Accompanying Family Members
Not required to be included
352. A person is not required to include in an application a non-accompanying common-law partner or a non-accompanying child who is not a dependent son or a dependent daughter within the meaning of subsection 2(1) of the former Regulations and is a dependent child as defined in section 2 of these Regulations if the application was made under the former Act before the day on which this section comes into force.
Requirements not applicable
353. If a person has made an application under the former Act before the day on which this section comes into force, the following provisions do not apply to the person in respect of any of their non-accompanying dependent children, referred to in section 352, or their non-accompanying common-law partner:
(a) paragraph 70(1)(e);
(b) subparagraph 72(1)(e)(i); and
(c) paragraph 108(1)(a).
354. If a person makes an application before the day on which this section comes into force, their non-accompanying dependent children, referred to in section 352, and their non-accompanying common-law partner shall not, for the purposes of that application, be considered inadmissible non-accompanying family members, referred to in paragraph 42(a) of the Immigration and Refugee Protection Act, and are not subject to the requirements of paragraph 30(1)(a) or 51(b).
Family members not excluded from family class
355. If a person who made an application under the former Act before June 28, 2002 sponsors a non-accompanying dependent child, referred to in section 352, who makes an application as a member of the family class or the spouse or common-law partner in Canada class, or sponsors a non-accompanying common-law partner who makes such an application, paragraph 117(9)(d) does not apply in respect of that dependent child or common-law partner.
SOR/2004-167, s. 77.
http://www.canlii.org/en/ca/laws/regu/sor-2002-227/latest/sor-2002-227.html#Division_8___Non_Accompanying_Family_Members
Division 8
Non-Accompanying Family Members
Not required to be included
352. A person is not required to include in an application a non-accompanying common-law partner or a non-accompanying child who is not a dependent son or a dependent daughter within the meaning of subsection 2(1) of the former Regulations and is a dependent child as defined in section 2 of these Regulations if the application was made under the former Act before the day on which this section comes into force.
Requirements not applicable
353. If a person has made an application under the former Act before the day on which this section comes into force, the following provisions do not apply to the person in respect of any of their non-accompanying dependent children, referred to in section 352, or their non-accompanying common-law partner:
(a) paragraph 70(1)(e);
(b) subparagraph 72(1)(e)(i); and
(c) paragraph 108(1)(a).
Requirements not applicable
354. If a person makes an application before the day on which this section comes into force, their non-accompanying dependent children, referred to in section 352, and their non-accompanying common-law partner shall not, for the purposes of that application, be considered inadmissible non-accompanying family members, referred to in paragraph 42(a) of the Immigration and Refugee Protection Act, and are not subject to the requirements of paragraph 30(1)(a) or 51(b).
Family members not excluded from family class
355.
If a person who made an application under the former Act before June 28, 2002 sponsors a non-accompanying dependent child, referred to in section 352, who makes an application as a member of the family class or the spouse or common-law partner in Canada class, or sponsors a non-accompanying common-law partner who makes such an application, paragraph 117(9)(d) does not apply in respect of that dependent child or common-law partner.
SOR/2004-167, s. 77.
You might also want to read this:
http://www.cba.org/cba/cle/pdf/Rubinoff2.pdf
Excluded relationships (9) A foreign national shall not be considered a member of the family class by virtue of their relationship to a sponsor if ... (d) subject to subsection (10), the sponsor previously made an application for permanent residence and became a permanent resident and, at the time of that application, the foreign national was a non-accompanying family member of the sponsor and was not examined.
Exception (10) Subject to subsection (11), paragraph (9)(d) does not apply in respect of a foreign national referred to in that paragraph who was not examined because an officer determined that they were not required by the Act or the former Act, as applicable, to be examined.
Paragraph 117(9)(d) excludes from the family class a foreign national where the foreign national was a non-accompanying family member of the sponsor (spouse, common-law partner8 or dependent child and dependent grandchild)9 and was not examined when the sponsor obtained their landing as a permanent resident.
Subsection 117(10) provides an exception to the application of paragraph 117(9)(d), as paragraph 117(9)(d) will not apply to a sponsored foreign national “who was not examined because an officer determined that they were not required by the Act or the former Act, as applicable, to be examined.”
Hope that helps