... in a pages widget without having to specify each one.

This is going to be a site editied by many and I would like to be able to select the page to exclude and automatically exclude all the subpages from the pages widget.

Is this possible?
And how can I do it...

thanks,
Tesha

I have the EXACT same question!!!

Someone please advise...

It would all depend on the widget you are using. If you are lucky, the widget will have that ability, otherwise you will have to edit the code and make some change to give you this functionality