Draw a histogram using two selected lines in a data file

In my data file I have 6 columns. 4th column is “energy” and 5th column is “cellID”.As an example
energy / cellID
3.4 / 1
3.5 / 2
2.1 / 3
4.3 / 1
2.1 / 5

same cellID comes several times. I need to fit a histogram using only these two columns (4 & 5). I need cellID in x axis and energy in Y axis.
Can anybody help me to do this. i don’t know how to extract only these 2 columns from the dat file.
Thank you
Pushpa

see my reply at:
root.cern.ch/phpBB2/viewtopic.php?t=1038

PLEASE do not post the same question to different places.

Rene