How to generate a name for computer in ASP.NET?

Question

I want to automatically generate a host name whenever user log in into the web.When they click the button log in, the system will automatically create a pc name (in another page)to them and the data automatically save in excel for record.

 

But, the problem is, I want to create a pc name including company name eg; PENN + department name from what they have choose from drop down list in login form, example they choose IT + any 4 of random number.

 

Please help me, i do not have any idea for this calculation and i am still new in this asp.net.