How is this for an idea?
You are a Spetz Naz team with Viet Cong scouts, sent into the jungle escorting a Soviet pilot so he can steal a US Cobra. Once it's stolen it has to be flown back to the North. You could build on it by making the Spetz Naz have to take down air defenses along the flight route so that the chopper could get back safely. I'm sure you could beef the mission up with your own ideas.
I was going to do this mission myself but couldn't be arsed.