Hi,

I need your help.

Sheet 1: Produces a random alphanumeric string in about 200 variations,
depending on strict criteria.
eg. Criteria #23 is 2 letters, 3 numbers, a letter, a number - such as MH735D9

Sheet2: Has 50,000 items. It uses data in its page to decide which string
code it should use from sheet 1.
eg. Line 16843, item fits with variation #23, vlookup sheet 1 and get unique
code.

Trouble is, because it is already calculated on sheet 1, all the thousands
of items that fit criteria #23 will get the same code from the vlookup,
rather than a unique code.
eg. from above, all items fitting criteria #23 will get the code MH735D9

How can I make it so that they all have unique codes (as per the criteria)?

Thanks in advance. :)