Glen,
I have not done this so... But if you open up the Visual Basic Script
Editor you will see that much of the slides layout is done with scripting
functions. You'll also see a "Grid" control in the list of available tools.
Again I have not played with it but I see no reason you can't build a
"function" in the scripting to do as you want. If you give this a try
holler back and let us know how it works out.
Austin Myers
MS PowerPoint MVP Team
Provider of PFCPro, PFCMedia and PFCExpress
www.playsforcertain.com