Fw: Fax problem

[Gaby L / AutoGlobus2000 SRL]

Hi
 I want to rewrite "From filed" from header,but only when  To: Field is only 
numeric  (fax type)
It is:
 If To: nume...@domain.tld then  
      From replace with f...@mydomain.tld
Endif

It is possible (Canical?)
Thanks
Gaby