when you hit resend it brings up an editable msg window. my saved message has just a word to indicate what group it is - like friends or business etc..
you can erase it and type in the message you want and send. just try it and you will know what i mean, probably confusing to understand what i wrote.
I know... this is nothing like just calling a group and sending a msg, but the closest alternative and I use it everyday.
I wud be crazy to send the same msg to the same ppl everyday tho...
Rex.