Function to check and convert CanonicalName to DestinguishedName

ConvertTo-DistinguishedName.ps1

function ConvertTo-DistinguishedName{
[CmdletBinding()]
Param(
    [Parameter(Mandatory=$true,Position=0,ValueFromPipeline=$true)]
    $CanonicalName
)
    Begin{
        # StringBuilders used to build DestinguishedName and LDAP query
        $dn = [System.Text.StringBuilder]::new()
        $ldapQuery = [System.Text.StringBuilder]::new()

        # Static variables
        $objectTypes = 'OU','CN','DC'
        
        # StrictMode bypass
        $r = ''
    }
    Process{
        [void]$dn.Clear()
        $arrParts = $CanonicalName.Trim('/') -Split '(?<!\\)/'
        foreach($part in $arrParts){
            if(!$part){
                Write-Error "CanonicalName '$CanonicalName' incorrect"
            }
        }
        # Adding DC
        [void]$dn.Append($($arrParts[0].Split('.')|ForEach-Object {[string]$r += "DC=$_,"} -End {$r.Trim(','); $r = $null}))
    
        if($arrParts.Count -gt 1){
            # Check if leaf object is located within one or multiple OUs
            if($arrParts.Count -gt 2){
                # Adding OUs
                foreach($part in $arrParts[1..($arrParts.Count -2)]){
                    [void]$dn.Insert(0, "OU=$part,")
                }
            }
    
            # Adding leaf
            [void]$dn.Insert(0, "=$($arrParts[$arrParts.Count - 1]),")
            foreach($o in $objectTypes){
                [void]$ldapQuery.Clear()
                [void]$ldapQuery.Append("LDAP://$o")
                [void]$ldapQuery.Append($dn)
                try{
                    $works = [adsi]::Exists($ldapQuery)
                }
                catch{
                    if($_.Exception.HResult -ne -2146233087){
                        throw $_.Exception
                    }
                }
                if($works){
                    break
                }
            }
        }
        if(!$works){
            Write-Error "The object '$CanonicalName' could not be found"
        }
        else{
            Write-Output "$o$($dn.ToString())"
        }
        # Cleanup
        $works = $false
    }
    End{
        # Nullify StringBuilders
        $dn = $null
        $ldapQuery = $null
    }
}