splitCSV_powershell.txt

# Read parent CSV
$InputFilename = Get-Content 'C:\working\splitCSV\testSplit.csv'
$OutputFilenamePattern = 'output_done_'
$LineLimit = 2000

# Initialize
$line = 0
$i = 0
$file = 0
$start = 0

# Loop all text lines
while ($line -le $InputFilename.Length) {

    # Generate child CSVs
    if ($i -eq $LineLimit -Or $line -eq $InputFilename.Length) {
        $file++
        $Filename = "$OutputFilenamePattern$file.csv"
        $InputFilename[0] | Out-File $Filename -Force # Writes Header at the beginning of the line.
		$InputFilename[$start..($line - 1)] | Out-File $Filename -Force -Append
		# Original line 19 with the addition of -Append so it doesn't overwrite the headers you just wrote. 
        $start = $line;
        $i = 0
        Write-Host "$Filename"
    }

    # Increment counters
    $i++;
    $line++
}