DecodeUTF8.ps1

$valuesToDecode = @(
    "éé"
)
Function DecodeStringToAscci($string) {
    If($string -like "*ê*") {
        $string = $string.replace('ê','ê')
    }
    If($string -like "*é*") {
        $string = $string.replace('é','é')
    }
    If($string -like "*è*") {
        $string = $string.replace('è','è')
    }
    If($string -like "*à*") {
        $string = $string.replace('à','à')
    }
    If($string -like "*À*") {
        $string = $string.replace('À','À')
    }
    If($string -like "*Ê*") {
        $string = $string.replace('Ê','Ê')
    }
    If($string -like "*ô*") {
        $string = $string.replace('ô','ô')
    }
    If($string -like "*ù*") {
        $string = $string.replace('ù','ù')
    }
    If($string -like "*ï*") {
        $string = $string.replace('ï','ï')
    }
    If($string -like "*æ*") {
        $string = $string.replace('æ','æ')
    }
    If($string -like "*ç*") {
        $string = $string.replace('ç','ç')
    }
    If($string -like "*Ç*") {
        $string = $string.replace('Ç','Ç')
    }
    return $string
}

$valuesToDecode | foreach {
    DecodeStringToAscci $_
}