Redirecting with HTACCESS from iindex.php?r=sdft2345 to just dft2345 , possible?

Lets say i have the next link:

mydomain.com/index.php?r=sdft2345

and i want it to be:

mydomain.com/sdft2345

is it possible? if not so how short can i make it? I failed to understand the writing of HTACCESS and if someone can be a bit more clear about it, il be glad.

Thank you very much.