Marcus, I think he means: define a template with an "autonumber" text box (a'la Access, e.g.). Open the template the first time, and the text inside the text box would be "001". Make changes and save off. Next time the template is opened, it would read "002", and so on...
Is this right, Carl?
(p.s. if this is the case, try looking into the variables palette and binding to a data set)