I think that Prograssive Systems Solutions does custom programming on the AR modules. http://www.progsys.net or 407.523.7676
They have a lot of custom AR solutions already written, one of which may meet your need out of the box.
much appreciate the quick reply. Will contact them.
I hope your project goes well. We're evaluating their Fixed Assets module and also their Collections add-on.
Where are you located?
Our team works wtih a large Dynamics SL customer base providing unique solutions. We would be happy to chat with you regarding your needs. www.DynamicTSI.com. You can call me at 404.790.1029.
Might be simpler and more manageable to use two invoices and combine them when you send them to the client. MUCH quicker and simpler to code and maintain. (add "F" and "C" to the invoice number for internal use, and just send to the client one invoice.)
I like Toni's suggestion. It keeps it simple. What does your invoice need to look like? Do you need to show a Fee line and a Cost line?