INDIRECT.EXT function, PULL function
 

Correct Syntax for use of pull

I have a spreadsheet in which I am trying to use Harlan Groves UDF to collect data from over 100 closed workbooks.
I have installed the UDF correctly I believe, as it shows as a user defined function.

Directory path is stored as a hyperlink in B1,
Filenames listed as hyperlinks from A4 to A100 (and growing)
Sheet Name is constant "Ingredient detail" but I have also tried putting this in F1
Cell references are constant E10

The file listing is updated by autorun macro (I found but cannot credit) each time the workbook is opened as more files may have been added to the directory since last opening. It creates an alphabetically sorted list of hyperlinked filenames.

I have gotten as far as
=pull("'"&B1&"\"&"["&A4&"]"&"Ingredient detail"&"'!"&"E10")
also
=pull("'"&B1&"\"&"["&A4&"]"&F1&"'!"&"E10")

each returns #VALUE! error

Where have I gone wrong?

Thanks in advance any assistance appreciated.

Paul