I can successfully create a linked report on my SSRS server using the powershell script here.
[string]$webServiceUrl = "http://myssrsserver/ReportServer/ReportService2010.asmx"
$ssrsProxy = New-WebServiceProxy -Uri $webServiceUrl -UseDefaultCredential
#File name of new linked item
$itemPath = "Linked server test"
#Path of where the linked report should be created in
$parent = "/A folder"
#Report we are basing our linked report on
$link = "/Reports/A report"
#Create property object
$type = $ssrsProxy.GetType().Namespace
$linkPropertyType = ($type + '.Property')
$linkProperty = New-Object ($linkPropertyType)
$linkProperty.Name = "Linked report description"
$linkProperty.Value = "Linked server test"
$ssrsProxy.CreateLinkedItem($itemPath,$parent,$link,$linkProperty)
I can't work out how to set the parameter on the linked report. It's a single value parameter, and I want it to be hidden, use default checked, and set to the value I pass. The parameter has a list of allowed values, but I know what I want to set is allowed.