If i wanted to simply redirect /clients/page/
to /clients.php?view=page
i would use something as simple as this, it works great.
Option
I think you're looking for the [QSA] flag on the RewriteRule:
http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html#RewriteRule
That should cause mod_rewrite to preserve your original query parameters.
RewriteRule ^clients/([^/]+) /clients.php?section=$1 [QSA,NC]
I think you can use the [QSA] flag, which stands for Query String Append. This means that you can add variables to the Query String easily:
RewriteRule ^clients/([^/]+) /clients.php?section=$1 [QSA, NC]