In init.sqs (or whereever) "1"setRadioMsg "Follow me around"
Now give the chopper a hold waypoint somewhere out of the way. Create a trigger and synchronise it to the hold WP
Activation box: Radio alpha
Type: switch
On Activation: chopper1 doMove getPos loon1; "1" setRadioMsg "null"
You might prefer doFollow or join instead of doMove (or move). Syntax not guaranteed, look it up. Search the forum for more on switch triggers (which you need for your other question too) or look at the new tutorial in Pending in the Ed Depot.
Somebody asked about how to make a chopper land at the player's location the other day. It's amazing how often this sort of thing happens - a question isn't asked for weeks or months and they it turns up twice in three days.
Anyway, choppers are awkward things at the best of times and what you are proposing is even more tricky than the usual. I strongly suggest you start by learning how to make a chopper go to a fixed location, land, wait for the player's squad to get in, then fly away.
You will need:-
a switch trigger
an invisible H
some waypoints
the command land
there are a couple of tutorials and loads of posts on the forum, so have a hunt around.