Pad middle column

$sampleText = "A/R                                      Patient                                  TIKASI, DEREK  00000000             00000000             Inpatient                                "
$maxLength = 1500

$firstDigitPosition = [regex]::match($sampleText,"\d").Index

$padChar = " "
$padding = $padChar * ($maxLength - $sampleText.Length)

$finalRow = $sampleText.Substring(0,$firstDigitPosition - 1) + `
                $padding + `
                $sampleText.Substring($firstDigitPosition - 1,$sampleText.Length - $firstDigitPosition + 1)

$finalRow