[plug] gmail filters

Hi, um Google hasn't been particularly helpful here, so perhaps some of
you smart people can help :)

I am finding the filters in Gmail pretty restrictive.

I want to create a simple filter that finds everything in my mail sent
to a particular address, that is NOT already labelled then label it.

I have multiple accounts forwarded to gmail because it makes a great
always on IMAP inbox. The goal here is to grab all mails sent to a
particular email address, that have NOT been labelled by any other
filter and label it for that accounts "inbox".

I appreciate any ideas you might have.

Cheers.
D.