Tracy, the function CreateProcess execute an application file... your can't execute this function with one file that non application.

Your can tray with ShellExecute function, for execute a file non application. But this function don't wait...

if you want that execution wait until the application, then use CreateProcess... and find application related with your file non apllication (.xfdf) and execute that. In Solution Application of VFP, explain how get this information.

Good Luck.-