Nice Question. Never thought of that. Anyway after doing a bit of experimenting, I come to this conclusion.
As soon as external movie is loaded, you could retrieve the data ( not necessarily global ) from that clip, using regular syntax for accessing variables.
Suppose you do this. It wont work.
_root.mo.loadMovie("test2.swf"); // mo is movieclip
trace(f); // f is global var in test2.swf
I don't know but why the movieclip "mo" doesn't get loaded when trace(f) is reached.
Now, now add this somewhere _root.mo.loadMovie("test2.swf"); like _root.onLoad and in another move clip which will be used as button I add this
onClipEvent (mouseUp) {
trace(f);
} Then it would work.
In this case the external movie is loaded. So for now the second one is the solution available. If you want to update the data regularly, useEnterFrame clipEvent. If you get any other solution, post here.