Maybe I should explain the problem.
There are a number of user groups. Each user group must go to another OWN user group page after login.
As far as I can see I can't use the loginbox droplet because there is only room for a 'static' page there.
I'm now trying the template madoven, because there is already a login in the template, to get so far that it switches to another page after login.
Unfortunately I am not such a coder hence my question here.