About 200 members of the Alaska Air National Guard's 176 Mission Support Group and 176 Medical Group participated in an expeditionary skills exercise at Camp Mad Bull here June 8 to June 9.   Four of the mission support group's squadrons and the medical group performed individual training, cross-trained between units, and culminated their activities in a joint mass casualty exercise during the Polar Guardian 14-2 Mad Bull exercise.   This exercise emphasized the importance of exposing personnel to their other Airmen's jobs, showing how their functions interrelate and providing a more realistic training environment.   "It was eye-opening to see other [Airmen] doing their individual missions, coming together to accomplish one goal," said Staff Sgt. Peter Kanz, the training manager for the 176 Security Forces Squadron.   Collaborative group efforts such as these are not found within every wing. The groups achieved a significant amount of training and were afforded training  -- such as erecting shelters and staging large convoys -- outside their customary roles.    "It was a resounding success," said Col. Patty Wilbanks, commander of the 176 Mission Support Group and lead commander of the exercise. "We're looking to do more in the future."