MS Project 2007 VBA to retrieve tasks and custom fields

I have a simple MS Project file (2007) with just couple of tasks. I have also created a custom field called VBATest and assigned values to this custom field against the two project tasks.

I would like to retrieve a list of project tasks and the value assigned to the custom field like this;

ProjectTask | VBATest <--Custom field
------------|--------
Task1       | vba1
Task2       | vba2

I'm doing this from Access 2007 VBA as this is where the final code will end up. I can get most of it working, but I can't seem to read the custom field value from the Assignments object. Do you have Any ideas? Thanks

Here is what I have done so far.

Sub LoadPr开发者_如何学JAVAojectFile()

Dim pjApp As MSProject.Application
Dim FileToOpen
Dim Proj As MSProject.Project
Dim Project_Task As Task
Dim fd As FileDialog

Set pjApp = New MSProject.Application

If pjApp Is Nothing Then
MsgBox "Project is not installed"
End
End If

pjApp.Visible = True
AppActivate "Microsoft Project"

Set fd = Application.FileDialog(msoFileDialogFilePicker)
fd.Filters.Clear
fd.Filters.Add "Microsoft Project Files", "*.mpp"
fd.AllowMultiSelect = False
fd.Show
If (fd.SelectedItems.Count = 0) Then
    'Application.GetOpenFilename("Microsoft Project Files (*.mpp), *.mpp")
    pjApp.Quit
    Set pjApp = Nothing
    Exit Sub
End If

pjApp.FileOpen fd.SelectedItems(1)
Debug.Print "Project_Task_Name~CustomField"

Dim ass As Assignment
For Each Project_Task In pjApp.ActiveProject.Tasks
            If Not Project_Task Is Nothing Then

                For Each ass In Project_Task.Assignments
                    assignCFVal = assignCFVal & "," & ass.VBATestField '<<PROBLEM Line
                Next ass

               Debug.Print Project_Task.Name & "~" & assignCFVal
               assignCFVal = ""
            End If
        Next Project_Task

pjApp.FileClose pjDoNotSave
pjApp.Quit
Set pjApp = Nothing

End Sub

It turns out I don't need to use the Assignments object for this. The SetField method would return what I need as below;

For Each Project_Task In pjApp.ActiveProject.Tasks
            If Not Project_Task Is Nothing Then
              assignCFVal = Project_Task.SetField(FieldNameToFieldConstant("VBATestField"))
              Debug.Print Project_Task.Name & "~" & assignCFVal
            End If
Next Project_Task