Hi, my excel is as below. I have excel sheet. Column A, B, C, D stand for Room No, Company, Contract No and Rental.
Spreadsheet 1 look like this...

A2-01 ABC C201201002 $500
A2-03 ABC C201201003 $450
A2-01 GGG C201201001 $350
B2-03 GGG C201201001 $260
B2-03 XXX C201201005 $250


The difficult thing is each room might have 1 or more contract number and maybe more than 1 company staying. 1 company might have multiple contract. However, each contract is only attached to 1 company. For example, ABC might have Contract number C201201002 and C201201003, but these 2 contract number wont be re-used again for another company.

NOw the problem comes, I have another spreadsheet, it have the same Column A, B and C. HOwever, without Column D. How do I use "Index" or "Vlookup" to solve my problem?