IP Masquerading question

I am learning about IP Masquerading so I do not know a lot about it yet. My
question: Can I Masquerade an IP on my internal network to a whole different
IP once it goes through the firewall and if so how?

Thank You,

David Demland
Qa/Testing Manager
CADTEL Systems, Inc.
11201 N. Tatum Ste. 200
Phoenix, AZ 85028
(602) 953-4888
Fax: (602) 953-4833
ddemland@cadtel.com