Hey Dave, let me see if I understand, you want to forward a certain date range of messages to your local email client, from your virtual email client(gmail)?
As far as I know, Gmail is in beta form and has been for over a year. there is currently no feature for the purpose you specified. I have submitted a suggestion to the beta team that reads as follows
"Provide a means to select multiple emails you have archived or otherwise, from any date or date range, and send them to one or more email addresses of your choosing.
This should be an option either after a search result of your email is returned, or by manually selecting (check box) the emails you have stored, to be forwarded to any specified recipients."
I'm sorry there is no current solution for your situation at this time, outside of using your mac to access your gmail account, and individually selecting each email and choosing "forward" to sent it to your mac email account. A Mac is a very powerful machine, and you can utilize the "automator" to create a custom script to handle the task for you.
I am not sure what you are wanting to do with your emails once they are in your mac account, but if the end result is to print each one, you can do that from within gmail itself. If you just want a copy of them, they are perpetually saved in gmail also, until you reach your 2 gig limit.
I think if we knew more details about what your end result or goal is, we could come up with a means to an end in either a non-traditional, or more creative way. (not to mention you get 2gig of gmail free, and you have to pay for your storage on .mac)
Rocket
Rocket