The modules allow you to do on Unix (and Windows) to manipulate Excel files. I already told you that your existing approach of reusing Excel will not work on Unix, because Excel (and the technology used to communicate with Excel) does not run on Unix.

You will need to look at the modules I linked, and install those, maybe first on your Windows machine, and rework your program to use these modules. Then you will need to install these modules on your target machine(s) as well.

If you feel overwhelmed by this, contact your system administrator on how to install modules.