passing command line arguments to executable

[mcanjo]

I have an executable (I don't have access to the source code) that
processes some data. I double click on the icon and a Command prompt
window pops up. The program asks me for the input file, I hit enter,
and then it asks me for and output filename, I hit enter a second time
and it goes off and does its thing and when it is finished running the
Command Prompt goes away and I have my new output file in the same
directory as my executable and input file. I would like to be able to
batch process a group of files. I thought about using "os.spawnv()" in
a loop and at each iteration of the loop passing in the file in and
out names but that didn't work. Does anyone have any ideas?