Is there a way to change something in Tool->Options via a macro?

DTE.ExecuteCommand ("Tools.Options")

Dim p = DTE.Properties("ProjectsAndSolutions","BuildAndRun")
p.Item("MaxNumParallelBuilds")

Sub EditConcurrentBuilds()
    Dim p As EnvDTE.Properties = DTE.Properties("Environment", "ProjectsAndSolution")
    Dim item As EnvDTE.Property = p.Item("ConcurrentBuilds")
    Dim text As String = InputBox("Enter number of concurrent builds", "Concurrent Build Option")
    Dim v As Integer = Val(text)

    If (v > 0 And v < 5) Then
        item.Value = text
    End If
End Sub