CSV Batch splitter

csvSplit.bat

@echo off
setLocal EnableDelayedExpansion
GOTO checkvars

:checkvars
    IF "%1"=="" GOTO syntaxerror
    IF NOT "%1"=="-f"  GOTO syntaxerror
    IF %2=="" GOTO syntaxerror
    IF NOT EXIST %2 GOTO nofile
    IF "%3"=="" GOTO syntaxerror
    IF NOT "%3"=="-n" GOTO syntaxerror
    IF "%4"==""  GOTO syntaxerror
    set param=%4
    echo %param%| findstr /xr "[1-9][0-9]* 0" >nul && (
        goto proceed
    ) || (
        echo %param% is NOT a valid number
        goto syntaxerror
    )

:proceed
    set limit=%4
    set file=%2
    set lineCounter=1+%limit%
    set filenameCounter=0

    set name=
    set extension=

    for %%a in (%file%) do (
        set "name=%%~na"
        set "extension=%%~xa"
    )

    for /f "usebackq tokens=*" %%a in (%file%) do (
        if !lineCounter! gtr !limit! (
            set splitFile=!name!_part!filenameCounter!!extension!
            set /a filenameCounter=!filenameCounter! + 1
            set lineCounter=1
            echo Created !splitFile!.
        )
        cls
        echo Adding Line !splitFile! - !lineCounter!
        echo %%a>> !splitFile!
        set /a lineCounter=!lineCounter! + 1
    )
    echo Done!
    goto end
:syntaxerror
    Echo Syntax: %0 -f FilePath -n NumberOfRowsPerFile
    goto end
:nofile
    echo %2 does not exist
    goto end
:end