Thats easy to do when making your screen in flash. Dont know if can be done with traditional screens
on (press) {
fscommand ("VBMacro","Button down script");
}``
on (release)`{
fscommand ("VBMacro","Button release script");
}
What screen/screen designer are you using?
If you are not using a custom screen maybe you can modify the flash mach nation to fix your needs
Regards
Pablo