Public Class Eval
        Private setString As String
        Private codeString As String
 
        Public Sub addSet(ByVal code As String)
            setString &= code + vbCrLf
        End Sub
 
        Public Function Evaluate(ByVal expr As String) As Double
            addCode("Option Explicit Off")
            addCode("NameSpace n")
            addCode("Public Class t")
            addCode("Public Function f() as double")
            addCode(setString)
            addCode("Return " & expr)
            addCode("End Function")
            addCode("End Class")
            addCode("End NameSpace")
 
            Debug.Write(codeString)
 
            Dim ASM As [Assembly] = CreateAssemblyFromCode(codeString)
            ' ... und ein Test der Assembly:
            Dim O As Object = ASM.CreateInstance("n.t")
            Dim T As Type = O.GetType()
 
            Dim MI As MethodInfo = T.GetMethod("f")
            Return MI.Invoke(O, Nothing)
 
        End Function
 
        Private Function addCode(ByVal code As String)
            codeString &= code & vbCrLf
        End Function
 
        Private Function CreateAssemblyFromCode(ByVal Code As String) As _
          [Assembly]
            ' Assembly aus VB.NET-Sourcecode in einem String erzeugen:
            ' CodeDomProvider für VB.NET erzeugen
            Dim CDP As CodeDomProvider = New _
              Microsoft.VisualBasic.VBCodeProvider                      ' 
            ' Compiler erzeugen
            Dim Compiler As ICodeCompiler = CDP.CreateCompiler()                _
                       ' Compiler-Parameter erzeugen
            Dim CP As New CompilerParameters
            CP.GenerateInMemory = True
            ' Compilieren und Compiler-Ergebnis ermitteln
            Dim CR As CompilerResults = Compiler.CompileAssemblyFromSource(CP, _
              Code)
            ' Im Fehlerfall Nothing zurückgeben
            If CR.Errors.Count <> 0 Then
                Return Nothing
            Else
                Return CR.CompiledAssembly
            End If
        End Function
 
    End Class
 
    Sub Test()
 
        Dim set1 As String = "x = 3"
        Dim set2 As String = "y = 4"
        Dim expr As String = "(2*x+3*y)*2"
 
        Dim eval1 As New Eval
 
        eval1.addSet(set1)
        eval1.addSet(set2)
        Dim result As Double = eval1.Evaluate(expr)
 
        Debug.WriteLine("Wenn " & set1 & " und " & set2 & " dann " & expr & " =" & _
          "" & result.ToString())    
 
    End Sub