As2.0 and AS3.0 communication

i m updating my e-learning course player project with Flash cs3 and AS3.0. the old version of course player was in As2.0. which load cousre swf files .
it was working fine Flash8 As2.0.
the player load course swf. the loaded course swf on a specifec frame call a method like this
_level0.setButton(2) method from course player;
The setButton(parameter) method defination is in new courser player. the loaded movie which is in Actionscritp2.0 not finding this method
in new course player which in Actionscript3.0. its working well with the old course player.
can any one give me solution to solve the issue.
i can’t make changes in course swf files b/c there are thousand of course files