You may try this:
Dim Testsettings As String = "/Testsettings:"""
Dim Testcontainer As String = " /Testcontainer:"""
Dim Resultsfile As String = " /Resultsfile:"""
Dim Quote As String = """"
Dim p As New Process()
p.StartInfo.FileName = Environment.GetEnvironmentVariable("VS110COMNTOOLS")
& "..\Ide\MSTEST.EXE"
p.StartInfo.Arguments = Testsettings & rwSettings & Quote & Testcontainer
& rwContainer & Quote & Resultsfile & rwResults & Quote
p.Start()