Modifying the LWPDetails page in MS Project 2007 Server Web Access

[haitifox]

Hello,

I have a very specific question, but maybe someone here can help me: I want to develop a customized solution for a project proposal. The MS standard is an aspx file named LWPDetails.aspx. I neither manage to start the page in Visual studio2005 (since it has two master pages and inherits from some application page I cannot find) nor can I make many changes without running in "unknown" sharepoint errors...

any help?

Thanks a lot in advance
Thorsten