En este link encontré informacion útil para este tema:
http://stackoverflow.com/questions/16193678/batch-file-detects-drive-letter-of-the-usb-flash-drive-its-on-then-opens-cmd-pr
en resumen es esto:
@echo off
set drive=%~d0
echo %drive%
pause
http://stackoverflow.com/questions/16193678/batch-file-detects-drive-letter-of-the-usb-flash-drive-its-on-then-opens-cmd-pr
en resumen es esto:
@echo off
set drive=%~d0
echo %drive%
pause