Ok, I got a bit further in my research:

on one of the MS sites it specified that the querry (the command specified in the .SelectCommand property) is automaticly executed by the object which is .DataBound to the SQLDataSource.

This means it happens too late for me - when the server is done and the client has the control.

I also know that I should be able to trigger the querry myself with .Select(). However, it wants a DataSourceSelectArgument - which i have no clue on how to pass that one, given the command is already in the .SelectCommand.

Anyone whant to give it a shot? (I have a feeling there has to be an easier way to do this)

Thanks!