Export in second Frame (Linkage Options of MovieClip)

I have several large MovieClips that are exported as classes for ActionScript in the symbol properties.

I’d like to uncheck the Export for First Frame checkbox and manually Export them for the second frame, but i haven’t the slightest on how to do this.

Example:
Class: OtherMedia
Base class: flash.display.MovieClip

Any help is much appreciated.

Thanks,
Ben Bart