Eligibility? Function

Hello all! In the attached, I'm trying to put together a type of eligibility function. or something haha

(car sales pay sheet)
So if a salesperson has to split a deal with another, the sheet needs to know if the salesperson using the spreadsheet "signed the deal" or not. If not, then the product formula (hidden in column S) needs to not include that car deal in its formula.

Endgame being, if you had to split a deal, but did not sign it out, that deal's product (or lack of) does not effect your product % numbers for the month.

My formula columns are hidden to the right of the sheet with white on white type

any help or direction would be greatly appreciated!

may2014.xls

It will have to be a user input. Whenever the user inputs that a deal was split with another salesman (indicated by text in the Split Consultant column), there will have to be some way for the user to specify whether or not they signed out the deal. If they did, then the Product % factors in, if they did not, that particular deal needs to be omitted from the Product % formula.

Does that clarify?