If you keep the .bb file and the .png file in the same directory, it seems to work with this code:
Graphics 800, 600, 0, 2 SetBuffer BackBuffer() Toolbarimage=LoadAnimImage("toolbar.png",24,24,0,70) MaskImage ToolbarImage,255,255,255 Repeat Cls DrawImage toolbarimage, 0, 0, Rand(54) - 1 Flip Delay 20 Until KeyHit(1) End