VLOOKUP problem

Hello,

Ok... I cannot get this to work.

I have a workbook with 2 spreadsheets, A and B. S'sheet A has 10 columns and maybe 5000 lines. Column C has a GlobalID, columns I and J have dates. S'sheet B has a single column, which is also a GlobalID. It is a fact that B is a subset of A.

I want to:

1. Lookup IDs from S'sheet B on A.
2. If there's a match, then copy the contents of S'sheet A's columns I and J into S'sheet B 's columns C and D (which are empty at this point)

I've tried, but have been unsuccessful. I always get #REF.

This is the formula:

C2=VLOOKUP(A2,SheetA!C2:C4819,9,FALSE)

Where
C2 = cell C2 from Sheet B
A2 = cell A2 from Sheet B

Thanks in advance.