I wrote some code to do essentially the "opposite", that is, import the structure into excel of the current Inventor assy.
Some code tweaking will be necessary to suit your filing structure, and iProps that you wish to import (we have several custom ones). (Plus no doubt you will find more efficient ways of doing some things. This is not documented/commented as fully as it could/should be..)
Place this code into an Excel code module, and run RetrieveInvAssyDetails()
This will overwrite any cell content, so the best be is to use a new sheet.
Have fun.
Edit: you should start by modifying line 38. All our file names should start with 700... hence this line.
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