Grid of Custom Controls??

Question

I have an application that needs an interactive editor.  The editor is basically a "spreadsheet" grid that only contains colors and geometric shapes drawn by the code.  I need to have events tied to each of the "cells".  I have seen grid and spreadsheet classes out there but my needs are so basic that the overhead of these sheets is burdensome.

My question is, do I make each cell a custom control?  I will need several hundred available at one time. During the actual editing process, speed is no real issue.  But when the programs switches from edit mode to run mode, I need to be able to just display each graphic quickly in a scrolling fashion.  I am concerned that creating a large number of custom controls will be a large processor issue.  The screen would only show a several hundred of  a total of several thousand data points. 

I  hope this makes sense! 

Thanks