Batch script for removing extra symbols after extension

I try to develope my English skills that is why I going to write articles on English. Please enjoy :) 

Script which I have been using for deleting extra right's symbols after extension or other lookup string:

@echo off

setlocal EnableDelayedExpansion

set /p pth=Please input the path to the folder:

set /p ext=Please input the extension:

set replace=

for %%a in ("%pth%\*") do (

set fpath=%%~dpa

set fileVariable=%%~nxa

REM echo.!fileVariable!

CALL SET delPart=%%fileVariable:*%ext%=%%

REM echo.!delPart!

IF defined delPart (

CALL set string=%%fileVariable:!delPart!=!replace!%%

REM echo.!string!

IF defined string (

set "fullNameB=!fpath!!fileVariable!"

REM echo !fullNameB!

ren "!fullNameB!" "!string!"

echo "File: !fileVariable! was renamed to !string!"

)

)

)

pause