I'm not quite sure what you are trying to do here. You have code that you have written. Are you wanting to create an instrument driver with it which calls another instrument driver? Or, are you just building the .fp file and you want that .fp file to call the code for the SCXI instrument driver? Or, do you want the SCXI .fp file to call your code? If it's one of the last two cases, then open Instrument>>Edit. Here, you can attach your code to a particular .fp file. You could use either your code or your .fp file to associate it with other code or another .fp file. Let me know if you are trying to do something else.
J.R. Allen