Accessing programs stored locally

Hi

I would like to give my customers access to an Excel model which is stored locally. However, I would like to be able to serve more than one customer at the time – which options do I have?

1. At the same time, several customers have access to the same PC and they are able to open their own “read only” excel file without being able to see the other customers’ excel files? (I guess not ;-) )

1. At the same time, several customer can access the same server and open their own excel workstation and excel file?

1. Customers have access to different PCs and before they try to connect to one of them, they get a list of PCs which are not occupied (e.g. through my homepage)?    

Hope you are able to help me.

Kind regards

Carsten Berg