i hope this is wat u means
manaul:
pan_setbmap(PANEL*,var type,var num,BMAP*);
Replaces a bmap of a panel element.
Parameters:
PANEL* Panel pointer.
type Element type:
3 = button
4 = slider
5 = window
6 = needle
num Number of the element, starting with 1. If the element contains several bmaps, like a button, the digit behind the decimal gives the number of the bmap to be affected (e.g. 0.0 = bmapOn, 0.1 = bmapOff, 0.2 = bmapOver of the first button).
BMAP* Bmap pointer.
Remarks:
The changed element is not saved by game_save.
Examples:
// change the bmapOff of a panel button
pan_setbmap(mypanel,3,1.1,newbmap);