>Basically I have an exe on a network drive and I want it to be run by only one person at a time. Now when you try to copy over an exe that is in use on another computer, the OS tells you so. So I figured there must be some command that would tell me if the program is in use anywhere else. I could put that command at the beginning of the program to and have it exit if the exe is being run by two people. Is any of this possible?

USE a table EXCLUSIVELY. If you can't open that table without error, then someone else is using the .EXE, so exit.