The only interest CIC might have in your mortgage is if the scheduled payments being debited from your bank account(s) reduces the account balance below POF required at any point of time during the process. As long as you ensure that doesn't happen, you are safe on the POF front.
If you meant using your property as POF, you can't. If you meant calculating the mortgage as fixed liability, CIC isn't keen to know your personal balance sheet, they just want you to confirm that you have at least as much liquidity as required by them in terms of POF.
Hope this clarifies. All the best!