Dim myMthdBuilder As MethodBuilder = myTypeBuilder.DefineMethod("MyMethod", _
                    MethodAttributes.Public, _
                    returnType, mthdParamTypes)
  
    ' We will assume that an external unmanaged type "LegacyNumber" has been loaded, and
    ' that it has a method "ToString" which returns a string.

    Dim unmanagedMthdMI As MethodInfo = Type.GetType("LegacyNumber").GetMethod("ToString")
    Dim myMthdIL As ILGenerator = myMthdBuilder.GetILGenerator()
  
    ' Code to emit various IL opcodes here ...
    ' Load a reference to the specific object instance onto the stack.

    myMthdIL.Emit(OpCodes.Ldc_I4, addrOfLegacyNumberObject)
    myMthdIL.Emit(OpCodes.Ldobj, Type.GetType("LegacyNumber"))
  
    ' Make the call to the unmanaged type method, telling it that the method is
    ' the member of a specific instance, to expect a string 
    ' as a return value, and that there are no explicit parameters.

    myMthdIL.EmitCalli(OpCodes.Calli, System.Runtime.InteropServices.CallingConvention.ThisCall, _
                  GetType(String), New Type() {})

' More IL code emission here ...