Editing MS Project File from Excel VBA

First, i apologize if this question has been discussed elsewhere. I looked through your forum (found many good tips, btw - thank you) and didn't see any threads about it.

What i'm attempting to do is edit a Microsoft Project file from an Excel VB Macro. We have a program that populates most of the necessary fields of Project file automatically, but other critical fields (durations) will need to be entered manually. To expedite the process, i'm attempting to create an Excel template for the responsible parties to update and would like the macro to then update the Project file.

I realize there are easier methods other than macros to do this, but as there are 30,000+ lines, many of which are repeated, a macro would be the most efficient.

The only code i have been able to find that even links the two different MS programs is this:

Set ProjApp = CreateObject("MSProject.Application")
With ProjApp
    .Visible = True
   'xxxxxx
    .Quit
End With
Set ProjApp = Nothing

While it does somewhat link the two programs, i'm experiencing problems right off the bat and am fairly certain that is not the best way of doing what i'm needing.

Any advice, examples, or references would be much appreciated.

Thanks in advance,
thedude

Edit:

Because the question was pretty vague and there doesn't seem to be much info out there, i posted the question on google.groups too:
Link: Google Groups Question