set @cmd =  'rs -i "C:\rep.rss" -s http://localhost/reportserver -v custparam=70 -v orderparam=20 -l 0 -e mgmt2000 -t -b'

EXEC xp_cmdshell @cmd


The rep.rss file looks like this :

Dim format as string = "PDF"
Dim filePath as String = "C:\Reports\"
Dim fileN as String = "MyReport"
Dim fileName as String = filePath + fileN + ".pdf"

Dim reportPath as String = "/MyReports/Report1"

Public Sub Main()

    ' Prepare Render arguments
    Dim historyID as string = Nothing
    Dim deviceInfo as string = Nothing
    Dim showHide as string = Nothing
    Dim results() as Byte
    Dim encoding as string
    Dim mimeType as string = "application/pdf"
    Dim warnings() AS Warning = Nothing
    Dim reportHistoryParameters() As ParameterValue = Nothing
    Dim streamIDs() as string = Nothing
    rs.Credentials = System.Net.CredentialCache.DefaultCredentials

    ' Report Parameters 
    Dim parameters(1) As ParameterValue
    parameters(0) = New ParameterValue()
    parameters(0).Name = "cust_no"
    parameters(0).Value = custparam
    parameters(1) = New ParameterValue()
    parameters(1).Name = "order_no"
    parameters(1).Value = orderparam
    results = rs.Render(reportPath, format, _
        Nothing, Nothing, parameters, _
        Nothing, Nothing, encoding, mimeType, _
        reportHistoryParameters, warnings, streamIDs)

    ' Open a file stream and write out the report 
    Dim stream As FileStream = File.OpenWrite(fileName)
    stream.Write(results, 0, results.Length)
    stream.Close()

End Sub