I have an apache vhost configurations as below. I want all my requests from
somedomain.com/loadproduct?product=dell-inspiron-15
to be redirect
You can use (instead of RewriteRule ??):
RewriteRule ??
RewriteCond %{QUERY_STRING} (?:^|&)product=([^&]+) [NC] RewriteRule ^/?loadproduct$ http://someotherdomain.com/%1? [R=301,L,NC]