.htaccess allows to "post" (the right word would be GET) data in a querystring using a directory-like style
You have to activate the RewriteEngine and then write a rule to convert the querystring expected by your page in a directory-style sintax, in order to write these rules you have to use some regular expression to map the elements in the url that will be recognised as the variables and the respective values of you querystring
For example
if you want to rewrite a query string like this:
www.sitename.com/showimages.php?album=sea&photo=mysurf
in a query like this:
www.sitename.com/sea/mysurf
you have to write the sequent rule:
RewriteEngine on
RewriteRule ^([a-z0-9]+)/([a-z0-9]+)/?$ /showimages.php?album=$1&photo=$2 [NC,L]
here is an interesting and simple guide to ".htaccess URL rewrite" http://edward-designer.com/web/htaccess-url-rewrite-simplified/
I apologize for my bad English
Hope this helps