Hi Classic,
The the previous 2 said..sharjah is a good place to start although Ostend, Belgium is a good place for AN-12's. I flew as flight manager a couple of times on both types of aircraft and they are great fun.
Operators such as Bright Aviation, Khors Air and Volare have aircraft based in Ostend....you may want to try them but most likely they will not allow "joyriders".