Transform Web (XML) config in Web app ps1 (specify Microsoft.Web.XmlTransform.dll location in script)

<#
.SYNOPSIS
    You can use this script to easly transform any XML file using XDT.
    To use this script you can just save it locally and execute it. The script
    will download it's dependencies automatically.
#>
[cmdletbinding()]
param(
    [Parameter(
        Mandatory=$true,
        Position=0)]
    $sourceFile,

    [Parameter(
        Mandatory=$true,
        Position=1)]
    $transformFile   
)

Write-Host $sourceFile
Write-Host $transformFile

#Apply config transformation
function applyConfigTransformation($src, $xdt, $dst)
{
Add-Type -Path "C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v14.0\Web\Microsoft.Web.XmlTransform.dll"

try 
{
Write-Host 'applyConfigTransformation - Called'
$doc = New-Object Microsoft.Web.XmlTransform.XmlTransformableDocument
$doc.PreserveWhiteSpace = $true
Write-Host 'applyConfigTransformation - Load Called'
$doc.Load($src)
Write-Host 'applyConfigTransformation - Load completed'

$trn = New-Object Microsoft.Web.XmlTransform.XmlTransformation($xdt)

if ($trn.Apply($doc))
{
Write-Host 'applyConfigTransformation - $trn.Apply called'
$doc.Save($dst)
Write-Output "Output file: $dst"
Write-Host 'applyConfigTransformation - $trn.Apply completed'
}
else
{
throw "Transformation terminated with status False"
}
}
catch
{
Write-Output $Error[0].Exception
} 
}

applyConfigTransformation $sourceFile $transformFile $sourceFile