Which Way to the Front? (1970)

Brendan Byers III is a wealthy playboy who wants to serve his country as a soldier, but he has been classified as 4-F (Registrant not acceptable for military service). He recruits volunteers among his employees for a privately-funded mission in the Italian front of the war. Byers impersonate the German general Eric Kesselring, with the plan to order German troops to retreat and give way to advancing Allied forces. Unfortunately for Byers, the impersonation comes with complication. He has to deal with the real general's Italian mistress, while the German authorities are investigating Kesselring's involvement in the July 20 plot to assassinate Adolf Hitler.