Redirect with modified Host and URI from variable

Some correction needed in iRule. Go with this..

when HTTP_REQUEST {
	set clientname [string tolower[getfield [HTTP::uri] "/" 2]]
if { [class match [string tolower[getfield [HTTP::uri] "/" 2]] equals clientnames_dg] } {
HTTP::respond 301 Location "https://demo-$clientname.mydomain2.com/$clientname"
	}
}

Thanks