GUID to ImmutableID
https://gallery.technet.microsoft.com/scriptcenter/Convert-between-Immutable-e1e96aa9
Immutable ID to HEX (mS-DS-ConsistencyGuid)
1) ImmutableID auslesen
Get-MsolUser -UserPrincipalName john@cesarhara.com | select ImmutableID ImmutableID: kKfL2wwI+0W+rN0kfeaboA==
2) ImmutableID konvertieren
[system.convert]::FromBase64String(“kKfL2wwI+0W+rN0kfeaboA==”) | %{$a += [System.String]::Format(“{0:X}”, $_) + ” “};$result = $null;$result = $a.trimend();$result