Address Hiding on Cisco 7200

Here is a bit more explanation for the question that I hav asked.

I am doing an assignment where we have to tackle different scenarios. One such scenario is: There are 2 seperate businesses. one buys stuff from the other. The buyer has 40 sites and each of them would be placing orders seperately. is there a way , the router on buyer' side hide these 40 addresses and send the orders through one single ip address. I was thinking in the lines, of having the a virtual ip address that hides these 40 addresses and sends the requests. By this the router on the supplier's side wont need any changes as previosuly it used to receive the orders from a single ip address.

I am still a newbie and any help from you gurus would be appreciated.

Thank you Ankit Parikh

Network Address Transalation (NAT)