Redirect a non-existent subdomain to a regular URL

I have amalgamated all sites on a server to a multisite setup and all domains are now "parked" on the server: traffic.mg - all is well

An old domain which was set as a subdomain on shared server is now simply "parked" and redirected using the domain mapping plugin.

This subdomain is removed:
press.playingintrafficrecords.com

the contents are now moved to:
http://traffic.mg/assests/press

The multisite network domain is:
http://traffic.mg

In short I need to redirect:
press.playingintrafficrecords.com to http://traffic.mg/assests/press

Should this be done at the domain registrar level or can it be handled locally at the server?

Thanks in advance