seymour,
A couple of things come to mind:
1) FLIMPORT is a DOS-based utility (one originally shipped with Paradox/DOS) and it sounds like Paradox 7 is having troubles locating and/or running it.
You may need to create a PIF file (or whatever they're calling in XP) specifically for it *or* specify the full file path where it's located. (You might also need to specify 8.3 filepaths, depending on which Paradox 7 you're using. Remember: Paradox 7 for Windows 3.1 doesn't understand long file names.)
2) Stack overflow usually indicates a series of recursive ObjectPAL events, e.g. event A triggers event B, which in turn triggers event A. Eventually, Paradox runs out of space for keeping track of all that. That's the basics of the error.
Now, why is the error happening? Could be several things at this point, again depending on which Paradox 7 you're using. (Paradox 7 for Windows 95/NT had several patches, which are still available from Corel's site and those need to be applied each time you reinstall Paradox 7.32. If memory serves, and I freely admit it may not, some of those tweaks dealt with stack overflow issues.
On the whole, I'd recommend looking at something else for importing the ASCII data, e.g. something writtn using Paradox for Windows' built-in abilities, rather than an older DOS utility that may--or may not--run properly under the current versions of Windows. (Remember, MS has been trying to get us off of DOS apps for years now.)
Also, I'd consider using the ObjectPAL Tracer to view the events as they occur in your form, as that'll give you an idea of the specific events that are overflowing. In my experience, it's generally something that triggers multiple action events or something along those lines. That may give you a place to begin.
I know there's not a lot of specifics, but I hope the general ideas point you in the right direction...
-- Lance