AFAIK there's no built-in commands for it.

have you checked if there are existing apps that already do this?
anyways, here's a document that is a little out of date, but might go in the right direction:
http://www.auc.edu.au/conf/conf01/downloads/AUC2001_Lai_2.pdf

no, i haven't seen any app for this purpose.

thanks for the pdf, I will check this out!

cheers