Launch Windows Program from PHP

I'm probably just not Googling right... Short version: How can I launch a program for the current user sitting in front of a windows web server? Longer version: I've written a PHP app to migrate data from the FoxPro version of our product to the upcoming MySQL version. I have a self contained setup on an XP box consisting of XAMPP, DBConvert (a data conversion program) and the ODBTP client/server. Phase 1 is a PHP app the pre-preps the data through ODBTP to a local FoxPro DBC. Phase 2 is the DBConvert and Phase 3 is a PHP app again doing post-conversion stuff in MySQL. To help in automating the whole shebang I'd like to automatically launch DBConvert with a command line argument (for the right data conversion stored session). Whenever I Google I find stuff about launching background tasks or using things like popen to launch processes "inside" the web server. I don't care if the owner of the process is the user at the keyboard just that they can interact with it. And if its Christmas and I can get everything I want :)... I'd love for PHP to be able to watch the process and stay resident until it exits so at that point I can send a final bit of javascript that will cause "phase 3" to automatically start. Any ideas? Thanks! Matt