A bit clumsy but...

="C:\Documents and Settings\User\My Documents\Pictures\"&ROW()&".jpg"

Or if you are starting in the 2nd row add the -1.

="C:\Documents and Settings\User\My Documents\Pictures\"&ROW()-1&".jpg"

You could then do a copy paste special values to get rid of the
formulas.

HTH
Regards,
Howard

"Freddy" wrote in message
...
I would like to fill down so only one character changes sequentially, like
this:

C:\Documents and Settings\User\My Documents\Pictures\1.jpg
C:\Documents and Settings\User\My Documents\Pictures\1.jpg
C:\Documents and Settings\User\My Documents\Pictures\1.jpg