Need help with extension

Hi, I wrote an extension that does does some calculations on a complex array (keyed tree structure), writing back the results to the same array. As such, it includes ("C"-)code that traverses, reads, and writes PHP arrays. Some basic stuff is already done, but doesn't work. Also, the thing has to run under both Windows and Linux. I need somebody with appropriate experience to make sure I've got a properly working extension. Since the purpose of that all is very specific to my application and everything is done in a commercial context, I will pay for any help by the hour or a fixed amount. Thanks Ralf