Rewrite with Pattern

[Fat Bear Mail Services]

How would one setup Postfix that uses /etc/passwd for authentication so 
that e-mails of the pattern:

   [EMAIL PROTECTED]
is delivered to:

   [EMAIL PROTECTED]

where there is a 1:1 mapping between companyID and companyDomain?  For 
example:

   [EMAIL PROTECTED] >>> [EMAIL PROTECTED]

Note above that "acme" maps to "acmedesign.com".

Many thanks!
Steve Amerige
Fat Bear