Solved Left Padding In DOS Command

I have this simple script. It will create a new file contain 999-999.
If user enter 99 it must show 099. How to use the left padding here?

Thanks

@echo off
Set /P p_rr_fr= Please enter Running No From : || Set p_rr_fr=NothingChosen
If “%p_rr_fr%”==”NothingChosen” goto :sub_error

Set /P p_rr_to= Please enter Running No To : || Set p_rr_to=NothingChosen
If “%p_rr_to%”==”NothingChosen” goto :sub_error

echo %p_rr_fr%-%p_rr_to%>running_no.txt

goto:eof

:sub_error
echo Please key in Running No