I need to use an id number from a field in this database to open a corresponding file on a network drive. The open file script command doesn't seem to allow you to put any random name in, you need to specifically select a file. Is there another command that I could use to have the filename generated instead of having to select it?

Are we talking about opening other FM8 files? In that case use AppleScript to open the file. The applescript syntax can be completely calculated from the value of your field.

How do you select the program to open the file though? I tested this with a text file on my desktop. When I select the file, it recognizes it as a .txt file and opens it using the appropriate program. When I use a calculation to do the same thing nothing happens. It says file type unknown. Is there a way to tell it what program to use to open the file?