update-stssyncgpos.ps1

<#
.SYNOPSIS
Create GPOs that set the Administrative Template for "Default SharePoint Lists" as specified in a CSV.
The CSV can update (or create) multiple GPOs based on the column "gpoName".

.DESCRIPTION
The input CSV has 5 mandatory columns:
	gpoName		: Name of the GPO to update
	ou 			: the name of the OU to link the GPO to
	siteName	: Site name on Sharepoint
	listName	: Name of the listName
	stssyncurl	: properly formatted STSSync URL. See: https://msdn.microsoft.com/en-us/library/dd957390(v=office.12).aspx

The format of the list's name when connected to Outlook will be "siteName - listName"

The CSV I've used was partially generated by another script, get-allspolists.ps1 which generates the STSSYnc URLs in the correct format.

.NOTES
	Author		: Quinten Steenhuis
#>

Param(
	[String]$csvpath = Read-Host -Prompt "Path to CSV: ")

$stssyncrows = import-csv $csvpath

function test-gpo ($gpo) {
	return [bool](get-gpo -name $gpo -ea silentlycontinue)
}

$gpos = @()

foreach ($row in $stssyncrows) {
	if ((-not ($gpos -match $row.gponame)) -or (-not (test-gpo $row.gponame)) ) {
		new-gpo -name $row.gpoName
		new-gplink -name $row.gpoName -target $row.OU
		$gpos += $row.gpoName
	}	
	$valueName = ($row.siteName + " - " + $row.listName)
	$key = "HKCU\Software\Policies\Microsoft\Office\15.0\outlook\options\accounts"
	$gp = get-gpo -name $row.gpoName 
	set-gpprefregistryvalue -guid $gp.ID -context user -action update -type string -key $key -value $row.stssyncurl -valuename $valueName

}