Querying multiple cell maps in one go

[MVL at ivip.frw.uva.nl]

Today's question involves script-writing. I would like to create a
script that allows the user to select some region, and automatically
displays whatever data are available for that region. The data
consist of series of aerial photographs and map sheets of a
topographic map. If Grass knows just the region and the type of data
to be displayed, can it select the right files by itself? I would
also like to be able to save whatever is displayed by using an
r.mapcalc formula, and need some way to pass the required information
to r.mapcalc (ie which parts of which maps should be mapcalced?).

If I'm lucky, somebody else has already done something of the sort.
If I'm not, perhaps you can suggest some way to proceed...
Thank you for whatever help you can give!

Martijn van Leusen