Identifier matching in the at command

Hi.

I can't seem to find anything regarding the syntax for the
"identifier" from the at command. So far I discovered that
- I can match the windows that have the title begin with the same characters or
- I can match only one window by complete title or number or
- I can match all the windows.

I'm interested in matching only a list of windows (title or numbers)
or a range of numbers. Is this possible? If yes, how?

Thanks.
--
Fita Adrian