Hi there,
In theory, you are supposed to provide the original WP. Thats being said you still have the status. If you explain your situation and provide enough supporting evidence (approval letter,copy of WP...), they should be able to clear this out. Of course, no one can ensure it as the final decision is made by the officer, but many on this forum were in the same situation as you and reported being able to re-enter Canada.
You can apply for getting your WP replaced (
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=175&top=17), and show this to the officer as well.