How to open a reserved area where people can buy special offer

[Giovanni14]

Hi,
thank you for the help!
I need to open an area where a group of people can login with a unique user and password and when they are in they can buy products. For instance user:Mouse gives the access to 50 people. When one of this guy buy something should start the usual process of buying in virtuemart compiling the buyers form and the registration as single user to the complete website .
I did as usual in Joomla but when I login, everything I buy go to the cart of the user used for the login. How can I solve the problem?
Thank you
Giovanni