>I have a form, "history" and a method ProgressBar in the form which
>paints a red line on the form.
>
>The form calls a program parse.prg. This program makes reference
>to the ProgressBar method in form History.
>Something like:
>
>*Program Parse
>*...............
>EXTERNAL FORM HISTORY
>.... etc ...
>History.ProgressBar(...parameters...)
>

I believe you will find that your program runs the same with and without the EXTERNAL command because this is really the wrong usage of the command. The EXTERNAL command is not meant to give an object reference, only to alert the project manager of the existence of a form file, so you can call it with DO FORM.

For what you need to do, you should pass the form reference to the program when you call it.
From you form code:
DO Parse WITH THISFORM

And then in Parse.prg:

LPARA toCallingForm

toCallingForm.ProgressBar(...parameters...)