Excel has never been my friend 
I have a formula on a cell which is:
=VLOOKUP(B74,'R3 Stock 30-6-05'!$A$6:$F$5690,6,0)
Now from that, I "think" it's reading as:
Get the value from cell B74 on the current worksheet, then look through a range of A6 to F5690 on worksheet "R3 Stock 30-6-05" and return the value in column 6.
The thing that's thrown me is the "0" at the end, or to be more precise, the "Range Lookup".
Because as an example, the worksheet "R3 Stock 30-6-05" has several entitles of a product called "EUK930110A", it has 3 entries to be precise, 2 of these have a value of 0 (zero) in column 6, one entry has a value of 12169.
The cell that the VLookup formula is in therefore shows 12169. But what I don't understand is if I change on the the "0" cells to, say, 100, why it doesn't change the cell with the formula into read 12269.
Or am I thinking about this the totally wrong way?
In laymens terms, I think I understand the VLookup command, but I don't understand this "Range Lookup" parameter, why it's picked up the value of 12169 and why it doesn't change if I change other cells on the lookup worksheet that are not a zero!
Any help I'd really appreciate.

I have a formula on a cell which is:
=VLOOKUP(B74,'R3 Stock 30-6-05'!$A$6:$F$5690,6,0)
Now from that, I "think" it's reading as:
Get the value from cell B74 on the current worksheet, then look through a range of A6 to F5690 on worksheet "R3 Stock 30-6-05" and return the value in column 6.
The thing that's thrown me is the "0" at the end, or to be more precise, the "Range Lookup".
Because as an example, the worksheet "R3 Stock 30-6-05" has several entitles of a product called "EUK930110A", it has 3 entries to be precise, 2 of these have a value of 0 (zero) in column 6, one entry has a value of 12169.
The cell that the VLookup formula is in therefore shows 12169. But what I don't understand is if I change on the the "0" cells to, say, 100, why it doesn't change the cell with the formula into read 12269.
Or am I thinking about this the totally wrong way?
In laymens terms, I think I understand the VLookup command, but I don't understand this "Range Lookup" parameter, why it's picked up the value of 12169 and why it doesn't change if I change other cells on the lookup worksheet that are not a zero!
Any help I'd really appreciate.