How to retrieve the following product charateristics

Hi All,

I am looking at retrieving all the product no's by giving Category or Item Category group as the selection parameters.

For Eg. I would want the system to show me the list of products created under Category - MAT_SERVICE or I would want the system to show me the list of products belonging to Item Category group DIEN.

Any clue how can I do tht?

Kind Regards

Mahesh