Where can I find the syntax for the BEx command button?

What commands are available for the BEx (Excel) command button? I can find a few samples in the developer guide, but no comprehensive list.

Particularly I'm looking for a command for removing characteristics from drill down.

I want to make buttons for a plan query so that users who have no need for all the characteristics easily can limit the query. For this I need a button setting a filter value (since all chars have to be filled) and removing the char from drill down.

Tips for a list of command button commands or other suggestions on solving the problem?