Nested for loop example. http://hup.hu/node/125384?comments_per_page=9999#comment-1619486

ffoxprof.cmd

@echo off

setlocal EnableDelayedExpansion

for %%u in (a b c) do (
	set USER=%%u
	for /f "usebackq tokens=2 delims=/" %%p in (`find /i "Path" "Users\!USER!\AppData\Roaming\Mozilla\Firefox\profiles.ini"`) do (
		set PROFILE=%%p
		echo "profile: !PROFILE!"
	)
)