I find it ironic that you say you want to automate the process but you haven't presented any code saying what you have tried. Perhaps you should make an effort to write something and I am sure someone would be willing to help from there.

You are asking how to convert a csv file to an excel file. The point that is being made is that a csv file is an excel file. MS Excel opens CSV files with no intermediate processing needed.

Like has been said you can open csv native in excel, or if you actually want to do anything else with the data, better off not converting into .xls...a quote comes to mind: "this is a dead end". Keeping the data in text or at least database format allows for transformations/munging. Excel can provide..uhm..pie chart. Avoid Excel (especially) for any number work where dollar amounts (or jobs) are at stake, as it's the only (supposedly serious) spreadsheet that uses floating point math for calculations.
the hardest line to type correctly is: stty erase ^H