if ($domain =~ 'bbspink') {
$rewrite_uri = $uri->scheme()."://".$host.$domain."/test/read.cgi/".$category."/".$dat."/";
}
else {
$rewrite_uri = $uri->scheme()."://".$host.$domain."/test/read.cgi/c/".$category."/".$dat."/";
}
でいけるはず