It is not entirely clear from your post where the linking is done, but the link information is buried there somewhere, and when undug, could be used to to link an Access table to one in Project, me thinks.
On investigation it seems that MS Project 2007 can't open .accdb file, it can open a .mdb file though. Converting my database back to .mdb is not an option. I believe MS Project can open a .accdb via ODBC but I have no idea how to set up a data source for that. So it seems my best option is to use a macro to TransferSpreadSheet to Excel then copy and Paste Special (Paste Link/Text Data) into MS Projects entry table.