HTTP: respond 404 and redirect to url

There is first variant proposed to customer, but they need send to client side exactly 404 code.

you can send 404 with meta refresh using HTTP::respond command. the command should look like this except code is 404 instead of 200. anyway, i think it may not be good for SEOs.

Redirect to a custom error page when server response is matched with any specific code

404 Error Pages and Redirects for SEOs

just my 2 cents.