Hi 404
You could list him as an author and use the following format to show your affiliations (if they differ):
404 (1), Helpful programmer (2)
1 Where 404 works, 2 Where the programming person works
Or you could put an acknowledgement in the abstract, which normally goes after the discussion/conclusions but before the references, something like:
Acknowledgement
The author(s) are grateful for blah provided by blah etc.
Check your conference abstract guidelines, they may not allow an acknowledgements section in which case you could go with the author option (which if you couldn't have done the work without this guy, might be justified, perhaps discuss with your supervisors?).