Changing the Details field of a linked contact in a project
we love the feature that allows you to link a contact to a project. We use this to link our freelancers and providers to a project, and in turn it lets us run useful reports (such as, which freelancer has worked the most, and so on). We usually use the "details" field when we link a contact to include that particular contact's fees, so we can add that to the report and make calculations. However, some of us sometimes use this field to input some textual information, which makes it more difficult in terms of calculations.
Is there any way to restrict this "details" field when linking a contact to numerical values only? I know how to do this for custom fields but I can't seem to find a way to do the same for this particular field. Also, is there any way to add more than just "Role" and "Details" fields to a linked contact?