Sorry for not giving enough info. The file  used is a .stf file.
This file is created from an old dos based program (written in pascal-
I believe). The program is used for testing electricity meters. The
data is then required to do statistical analysis. Basically you are
describing the method I currently use. However I am trying to
automate the system as much as possible as we do hundreds of these
groups. I have not had time to try some of the suggestions previously
posted but when I do i will get back to you.