Count Function.

[KiwiCam]

I have a bitmap that i would like to display a portion of it over a period of time, but the bitmap is 140 pixels high. If it was 60 high, them I could just use the %cS tag to display a portion of it every second over 60 seconds and start again. Is it possible to get some sort of Count() tag implemented? Perhaps also the tag could have a time function to split it over every half second or quarter second say, or we could use it in conjunction with %t?  Perhaps there is already another creative way to do this with the Tags we already have?