Combination of VLOOKUP and CONCAT

Hello all!
I have the following situation:
Workbook A, Sheet 1 has reference numbers in Column A.
Workbook B, Sheet 1 has the same reference numbers in Column A, but also has multiple Description Lines in Column B.

I would like to use a combination of VLOOKUP & CONCATE to bring the multi-line descriptions from Workbook B into a single cell in Column D of Workbook A. Basically it would CONCAT all lines in Column B down until it finds the next reference number in Column A (down to the next non-blank cell in Column A)

Please see the pic for an example.
Any advice would be greatly appreciated.
Thanks!

I would recommend doing the concatenation in Workbook B.
In C2 put =B2&B3&B4&B5&B6

Then use this in D2 of Workbook A
=VLOOKUP(A2,'Workbook B'!A:C,3,FALSE)

It totally makes sense to do the merge in Workbook B...didn't even think of that.
However, I'd still want a way to automate the merge (I have a couple hundred reference numbers and don't want to do all of the "&" work)
Thanks for the reply!

Have a look at the CONCAT and TEXTJOIN functions

Any suggestions on CONCAT/TEXTJOIN Column B down to the next non-blank cell in Column A?

If you fill in the blanks of column A on Workbook B (A3:A6=0001, A8:A10=0002 etc)
Then in C2 and filled down

=IF(A2=A1,"",CONCAT(OFFSET(B2,0,0,COUNTIF(A$2:A$100,A2),1)))

Worked like a charm.
Thanks!!!

You're welcome.