batch file question...?

This batch file is going to display a form letter on the screen. Your letter will look like this( with the first, last, and department names changed for each printed letter. The user will execute the batch file with the first name, last name and department( as command line parameters) for any number of customers. Using only two evironmental variables, display the form letter on a freshly blanked screen with the values of FName, LName and the department in the correct places. THe user will need to read the letter before continuing on to the next customer. Only use the %1 positional variable in the batch file. can someone show me step by step what to do? :)