[Typo3] multiple lists in form and user's group based on his choice in form

[racco]

Hello!

I want to do a registation site, based on sr_feuser_register extension, but
unfortunately it does not support multiple lists! I want to have a list of
peoples interests and after they choose for example: computers, cars, health
I want to set their group to appropriate typo3 groups (computers, cars and
health). So they will be able to get special emails for groups, see the
members etc.

I have 2 questions:

1) How can I override the fact that multiple lists are not supported? Could
you suggest me any other solution to my problem?
2) How to do this, that user's group is based on his choice made in a form;
how to bit this? php? typoscript? how to connect those values?


racco