If i wanted to simply redirect /clients/page/ to /clients.php?view=page i would use something as simple as this, it works great.
/clients/page/
/clients.php?view=page
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]