Use mod_rewrite to changing URL?

Hello dear DP users.
I am really a n00b at mod_rewrite and don't really know how to use it.

For example if I would like to change rewrite the URL:

http://domain.com/index.php?page=forum&id=3538

Code (markup):

to

http://domain.com/forum/3538 /*Note this is only an example, I don't really know how the output could be formatted*/

Code (markup):

how can I do this with mod_rewrite?


Also if I would like to change:

http://domain.com/index.php?page=forums&action=viewtopic&id=86

Code (markup):

to

http://domain.com/forums/action/viewtopic/86 /*Note this is only an example, I don't really know how the output could be formatted*/

Code (markup):

How can I use mod_rewrite to make the link look as good as possible?

Thanks for all kind of replies.
regards

 

Try this example below.