Ok, I have two situations.

A registered user becomes a clubmember (sign-up)

A clubmember user becomes a registered user (sign-off)

When a registered user becomes a clubmember the following happens:

His single select field (cb_type) changes from nothing or 'ikke-medlem' to either 'senior', 'junior', 'æresmedlem' or 'støtte'.

When a registered user signs out of the club, the opposite happens.

I've tried creating two rules.

One for registered users, that checks the cb_type is changed (var1_ different from var_3), and of course I can create 4 rules that checks each the the cb_type types of memberships (which I'm doing currently).

One for clubmember users, that checks the cb_type is changed, and is set to one of the two 'non-member states' (which I'm also doing at the moment).

So that's a total of 6 autoactions, and I think it would be more elegant to have just two, but I can't make that work, so if somebody could help me out, that would be great.

This is hilarious.
Ok, the first part, a registered user becomes a clubmember is solved.
Simply entering this as the regexp

/(Støtte|Æresmedlem|Junior|Senior)/

made it work, I have no idea why this didn't work the last time I tried.

Now on to the second situation

Hey I must be more awake today, I made second situation work with

/(|Ikke medlem)/

I had tried with several others, but this matches both empty and Ikke medlem

So, case closed :-D

Darned, I've spent hours on this, very strange, but now it works, wohoo!