Permission Issues

We currently run Sitefinity in conjunction with Aptify. One of the things we would like to do is to have a user area that is restricted to our users who are Company members. In other words, we would like to offer goods and services to users who are a member of our company, not just a site registrant.

Is there an easier way of doing this other than creating a web group (this will have to be assigned to ALL of our current members)? 

I also have another issue that somewhat relates to this. Our Company members (new web group), once logged in, can see the page in regards to the previous issue once we created the new web group and assigned it to a user who is a company member. We have contractual agreements with companies who would like to market to just our company members. They have set up a redirect page to send them to a marketing page if they would like to shop. They sent me the code for a form that would be invisible to the user that would get the information from the page and pass it to the server for verification.

My question is, how do I code this to get the data in variables? I have a sql statement as well as a stored procedure that will retrieve the information but I do not know how to assign it to the value in the form?