Its driving me crazy cause I know I have seen him in other parts, (and just recently too) but imdb has done a poor job of listing the actors and their characters. He is the major who was told by the general to explain the 5th column to hessler.
No, sorry, not the guy who was actually one of the 5th column MPs, but the guy who was in german uniform explaining the 5th column to Hessler. Actually, he seemed to be in charge of the infantry that accompanied hessler's tanks. Hessler reamed him out when his mine detecting unit fell behind the tanks and hesslers trailer hit a mine and several tank commanders inside the trailer were killed.
I think you are talking about that German officer who always wore a helmet and was around most of the time, and commanded the infantry when Hessler's tanks attacked Ambleve. The character's name was Von Diepel, and checking the Cast shown in IMDB, he was played by Karl Otto Alberty.
I guess you are right. I know I have seen him recently in another movie but don't see any movies listed under his name that it could have been. Maybe it was Kelly's Heroes, but I haven't seen that for years.