redirect/divert smtp relay mail

[gbcyoyo]

hello,

I am trying to figure out a way to configure our postfix relay server to send to different relays for the same domain.
All our hosts are configured to use relay.abc.com

domaine name=abc.com
in aliases file root is directed to an email adress ex root: whatever.abc.com

I need to be able to redirect to a different smtp relay depending what the from is
Ex:relay.abc.com receives ALL email but when it comes from=root@blahblahblah.abc.com relay=relay.abc.com it goes through the normal way for delivery.

Now, when a from=root@halbhalbhalb@abc.com then I need this email to be forwarded to another smtp relay server that will take care of sending the email at the right place ex relay.abc.com redirects from=root@halbhalbhalb.abc.com to
relay=otherrelay.abc.com

thx for the help