@echo off

setlocal ENABLEDELAYEDEXPANSION&pushd %~dp0

for /f "tokens=1,2 delims=." %%A in ( 'dir  /O:N /L /B /N  *.swf')  do ( 
set file=%%A 
set wordnodash=%%A
set wordnodash=!wordnodash:1=-!

ren %%A.swf !wordnodash!.swf

)
pause

cls
endlocal