@echo off
cd "D:\ssc_backup"
for /f "skip=3 eol=: delims=" %%F in ('dir /b /o-d /a-d *.sql') do @del "%%F"

REM Next line NOT needed if you add the WinSCP folder to your Windows  
REM PATH environment variable  
CD "C:\Program Files (x86)\WinSCP"  
Winscp.com /script=C:\efichain\GetFilesFromSFTPscript.txt