Hi and apologies for no one replying sooner. I don't know anything about UTM data (all my GIS data comes to me in LAT/LONG format) but I did some searching and found a very old SAS paper that should be able to help http://www.sascommunity.org/sugi/SUGI87/Sugi-12-89%20Chojnacky%20Tymcio.pdf. It's from 1987 but the math would still be right and the methods would still work.
Your other option is to look at PROC GPROJECT - i saw people converting LAT/LONG to UTM, so I imagine it should be able to go the other way as well.
Good luck and please post back what you end up using, I'm curious!
Have a good day
Chris
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