try this

=SUBSTITUTE(A1,".jpg","")

or

Select the column
Go to Data | text column | delimited | next | choose other option :
put an dot | next
select the jpg column in data preview | choose do not import (skip)
option | finish |


On Jan 17, 12:10*am, Problem poser <Problem
wrote:
I have copied hundreds of .jpg file names, using DOS, to copy them into a
listing within a worksheet. As a substantial amount are numeric with a file
extension I would like to split the cells to remove file extension to give me
a numeric result.

i.e.
"123.jpg" into a numeric "123" or "Many files.jpg" into "Many files"

The file names are variable in size and are either numeric or just characters
Thank you