Is it possible to put a function in the forum where you can start a topic in any subforum but can choose where to move the created topic?
I've seen it on some forums before and it's handy, like you don't have to go to the subforum to create a topic you can create it anywhere and just choose from a drop down menu where you want it.

Not sure what you're asking but isn't this similar to the moderation function 'Move'? You just go and create a topic then use the 'move' function to move the topic?

Yes. Put I want the users to be able to move the topic while they're creating it.
I'm just asking for a create a topic button where userscan choose the subforum from a dropdown list, so they don't have to go throuhg thewhole forum. They just click the button and choose everything then and there.

As far as I know, that's not possible I'm afraid.