Lol, I was going to say the same thing but You took the words out of My mouth anyways I'm going to repeate it then.
There is an AI Script that is called "enter transport", when you run it the units to be loaded and the transport (overlord, shuttle, dropship) have to be covered by a location.
what you want is that the dropship is loaded so you can just do it, in a corner or a place where no body sees the process and then move the dropship to where the map starts.. in case that the dropship is yours and you will be able to see the process what you do its to give the dropship and units for a computer say..player 8 maybe, make the units load and then give the dropship to yourself or the desired player and then move it
I hope you understood me because if i were you i wouldn't

have fun