You haven't mentioned whether you need to do this on a repeated basis (script), so this assumes you don't. Also assumes you are in the directory containing the files.
1. rm *.log
2b. This will give a list of all bat files, most recent is listed last
for i in `find ./*.bat | grep -v "whatever bat file you want to keep"`; do rm $i; done
Or, you could just temporarily rename/move the one bat file you want to keep, delete the remaining ones, and move it back. Before I run something like 2c I usually put "echo" or "ls" in place of "rm" to see that it's giving me what I expect. Then, once absolutely sure it's right, run it with the "rm" (since once you hit Enter on the rm there's no going back).