Well, the Red Cross submission window had already opened and closed by the time I got up today. The next submission date is 25 January 2021 at 8:00 (GMT +1). I don't know how many requests they do in a quarter but the Red Cross is probably not going to be of any help. :-(
I also checked with a US commercial provider I have dealt with in the past and he said they could not do it either. Apparently there is no US list or file that contains POW numbers linked to US ASN numbers or names in any accessible order.
It is a shame that when Len Rose originally set up his Stalag Luft IV website he didn't try to include POW numbers and ASN numbers, but he was probably doing his work then without computers, just typewritten lists. I don't think his website ever had a "look-up" function into a database of names and numbers. Just before Stalag Luft IV was closed in February, 1945 and the POWs were marched to the west (for the next 3 months), there were about 8,000 US POWs in the camp. Here is the story of one of them, Richard Hansen. The site was set up by Richard's son Jeffery. Richard's story is fairly typical of what the POWs experienced. I assume the man we are looking for had a similar story.
http://jefferyhanson.net/wwii/world_war_ii.html
Richard also saved his utensils:
http://jefferyhanson.net/wwii/pow_souvenirs.html
(You can right click on any image and open it in a separate tab then open that tab to get a better view).