change permalien

Hello;
I currently use this format to the permalink /% postname% /
So the night of the link fromat http://monsite.com/postname/
I wanted to send two variables in the link: http://monsite.com/postname/?var1=x&var2=y
but I wanted when I send the variables to change the link http://monsite.com/nouveaupostname/
I tried with. htaccess but I do not received this

is that someone can help me?

and thank you