Counting Form Cells

I have an app that a client will enter in a bunch of information about customers and who is the salesperson. What I am wanting to know is if there is a way for another form view to show a count of all the entries for a particular salesperson. So I would need it to go through each entry of the other form and check the salesperson then keep a count. I know how to keep a count and stuff but I do not know how to check each entry like that.