When using an App server setup the process (\vbasic\clickit) will by run on the server. It need to not be expecting any form of user input.
If it does need user input it will need to be run on the workstation by prefixing the command with [lcl] or [wdx] if a graphical application. In this case it should be noted that the program must reside on the workstation as would any files referenced such as \tmp\testfile.
If its a text mode application, designed to run from Windows command mode, and you want it run on the server you can programatically provide user input by opening it up as a pipe as in: OPEN (nn) "|\vbasic\clickit"