Hard to believe they can't edit a text file. If they can write an email, they can edit the file, but nonetheless. The first thing that comes to mind is maybe a two movies. The first movie would be where you would allow the saleman to enter the custom information. The client name, the location, what have you. Of course doing this method would require the saleman to enter the information each and everytime the movie is executed. Since Flash can't access file system (well it can, but that is another story) then the customized information will not be saved. (Really would be easier to just update a small XML file) When the saleman click a continue or submit button, the info is stored in a variable and the next movie is called.

This movie retrieves the info and populates it in the necessary textfields.

Of course, with all of these smart Flash users out there, there may be many many other options for you. This is just mine.