Replace Umlauts in #PowerShell with a replace function and regular expression

replaceUmlaut.ps1

$replaceUmlaut = {
    param ($Match)
    $characterMap = New-Object System.Collections.Hashtable
    $characterMap.ä = 'ae'
    $characterMap.ö = 'oe'
    $characterMap.ü = 'ue'
    $characterMap.ß = 'ss'
    $characterMap.Ä = 'Ae'
    $characterMap.Ü = 'Ue'
    $characterMap.Ö = 'Oe'
    $characterMap.$Match
}

[Regex]::Replace('Lüsterner Spaß mit öligen Äpfeln.', '([ÄÖÜäöüß])', $replaceUmlaut)