Saved from a previous post:

There's a limit of 240 characters per line when you save as .prn files.  So if
your data wouldn't create a record that was longer than 240 characters, you can
save the file as .prn.

I like to use a fixed width font (courier new) and adjust the column widths
manually.  But this can take a while to get it perfect.  (Save it, check the
output in a text editor, back to excel, adjust, save, and recheck in that text
editor.  Lather, rinse, and repeat!)

Alternatively, you could concatenate the cell values into another column:

=LEFT(A1&REPT(" ",5),5) & LEFT(B1&REPT(" ",4),4) & TEXT(C1,"000,000.00")

(You'll have to modify it to match what you want.)

Drag it down the column to get all that fixed width stuff.

Then I'd copy and paste to notepad and save from there.  Once I figured out that
ugly formula, I kept it and just unhide that column when I wanted to export the
data.

If that doesn't work for you, maybe you could do it with a macro.

Here's a link that provides a macro:
http://google.com/groups?threadm=015b01c32c5f%24b3d398d0%24a501280a%40phx.gbl