Help: how to target a certain frame in loaded external swf

can anyone help me with this? i have some buttons nested inside a mc (a scolling text field). i now want each of those buttons to load a same external swf ( it contents about 20 jpg) by clicking any one of them, but only to start and stop at certain frame(s) which correspond to that button. so to say, i can select different jpg from different buttons.
or, should i make each jpg a separate swf since 20 or so 400x300 jpgs would make a swf size too big?
any help would be appreciated.