Help Automating Google Groups membership edits

I would like to find a way to automate a task that I need to do repeatedly every Friday and Sunday.  Our firm uses Gmail and we use Google Groups for inter-company group mailings. One group is used to receive leads from several sources on the internet.  We have several weekend employees that rotate coverage to respond to these leads. Each employee covers one weekend per month.

So that their inbox isn't loaded with leads from days they are not responsible for lead coverage, I add them to the group each Friday afternoon and then delete them from the group each Sunday morning.  It is this adding and removing members from the Google Group that I would like to automate.  Ideally there would be a script that reads a text file of dates and names. The source file could be formatted as needed to simplify the script.

The script could run on my PC which is always on.  I am a domain admin for GMail.

I'm familiar with old-school batch scripting under DOS and Unix, but haven't kept up with the modern scripting languages.  Is this something that is feasible?  If so, what language would server best?

I know a few coders and could probably get this written if it's not too complicated.  I just need to know enough to explain what I need to a coder.

Thanks :)