I will improve on the suggestions given. The problem I am facing is, with the script I have, it deletes the existing histogram in the excel file. The input.txt.gz file looks something like this:

0.1
0.2
0.3
0.4
0.5
[download]

Those lines should just appear in the column A of excel sheet. I wish I can attach image here butI cannot. Hope you can understand what I am trying to say.