You could write a third program which launches both TVTool and PowerDVD, then associate *that* program with the DVD auto-run feature. Heck, that program could even be a DOS batch file if you wanted. (start c:\tvtool\tvtool.exe, start c:\powerdvd\powerdvd.exe)

Unless PowerDVD or TVTool have a shellExecute function built-in somewhere. I'm not too familiar with those programs. PowerDVD has a lot of features, maybe it's buried in there somewhere.