I did a bit of Excel programming in Python; a tool to extract, and sanity check, data from a spreadsheet, send it to a server and populate results back in the spreadsheet. The "Python Programming On Win32" book by Mark Hammond was a great resource http://shop.oreilly.com/product/9781565926219.do

http://oreilly.com/catalog/9781565926219 - Python Programming on Win32 has some good info and some stories on "batch processing" of office docs. Good case study on "Applied Biometrics" capturing of drug testing process. I've used the py/com stuff to do some of what you want - build xls files with "macros" for calculations, etc. You have the option of doing it in python or inserting the excel code into cells. You can also find other "excel" controls for python that create csv file versions of spreadsheets (so likely none of the macro capabilities) - same for perl, etc