Updating the Proxy Server Settings with Server Name, Username-WSUS

[vegesna]

Server details:- Windows Server 2008 x64 bit.

Programatically, I am able to automate WSUS sever with “WSUSSetup.exe /q
DEFAULT_WEBSITE=1”.

After installation, I tried to sync the server using flowing script entries.
SyncServer.ps1:-
[reflection.assembly]::LoadWithPartialName("Microsoft.UpdateServices.Administration") | out-null
$wsus =
[Microsoft.UpdateServices.Administration.AdminProxy]::GetUpdateServer();
$wsus.GetSubscription().StartSynchronization();

Sync failed with following error :
An HTTP error occurred.
WebException: The remote name could not be resolved: 'update.microsoft.com'
at System.Net.HttpWebRequest.GetRequestStream()
at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
methodName, Object[] parameters)
at
Microsoft.UpdateServices.ServerSyncWebServices.ServerSync.ServerSyncProxy.GetAuthConfig()
at
Microsoft.UpdateServices.ServerSync.ServerSyncLib.InternetGetServerAuthConfig(ServerSyncProxy proxy, WebServiceCommunicationHelper webServiceHelper)
at
Microsoft.UpdateServices.ServerSync.ServerSyncLib.Authenticate(AuthorizationManager
authorizationManager, Boolean checkExpiration, ServerSyncProxy proxy, Cookie
cookie, WebServiceCommunicationHelper webServiceHelper)
at
Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.SyncConfigUpdatesFromUSS()
at
Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.ExecuteSyncProtocol(Boolean allowRedirect).

Further investigating, I found by updating the Proxy Server Settings with
Server Name, Username and Password in "Microsoft Update Improvement Program"
Wizard. I am able to Sync Server with latest updates.

Help me to update the Proxy server settings programmatically using powershell.