and I think that you will need some Visual Basic for Applications programming. I do not have MS Project so I am unable to test this. The following is a snippet of code that should do what you want, more or less. Obviously you would need to 'top and tail' it.
Dim ref As Object
For Each ref In ThisWorkbook.VBProject.References
If ref.IsBroken = True Then
If you want a definitive answer I would ask at mrexcel.com