Invoice numbering?

[ljubo_gr]

Please, dear Excel super master users.
I have three(1.2.3) sheets, columns A and B on all three. In column B should be invoice number generated inserting data in A column, like, when typing "Bill" in A1, that should result MRE-INV-01 in B1. BUT, when typing "Jelen" in A1 on Sheet2, should be MRE-INV-02. and so on.
Invoice numbering should be generated by vlookup, Sheet1 to vlookup on sheet2&3, Sheet2 to vlookup sheet1&3... Then, probably IF function,,,, i don't know

 

[ljubo_gr]

Bump

Data will be entered in Q (col 17), sometimes also in S column, like, when i have 5 invoices for South(sheet2), then i enter in S column last number of South invoices(445 +5 =450). Numbers from 445 to 450 should be taken(not free), and i need error message to warn me! Another problem, every time i correct spelling in Q col, then another invoice number is generated Also, data should be entered in Q first then if i need to add invoices, in S col. Also, i need error message when entering in S first, because of Q row empty.

 

[ljubo_gr]

Solved thanks to:

Andreas Killer from Microsoft Community

http://answers.microsoft.com/en-us/...umbering/131d96b6-18f0-4a3b-908a-b5087854bc2e


and AlphaFrog.....this forum
Thanks!
Sorry for being pain in the a