i´m not surre if i understand you right
maybe that helps

PANEL test_pan =
{//...........................................
bmap = "slot_bg.pcx;";
pos_x = 0;
pos_y = 0;
button (130, 102, "p.bmp", "p.bmp", "p.bmp", function_onclick, NULL, NULL);
//tje button pos must be into the panel or i dosnt´t works
flags = VISIBLE;
}