Possible match and index formula needed please
 

Hello all I was wondering if any one could please give me advice on my current problem with excel. I need to compare and copy values between two different sheets.
I receive an invoice every month which contains a lot of the same data is there a way I can compare the values in columns f,g and j and if they all match insert the value from L from my old invoice to my new one. Any help would be greatly appreciated.

Thanks

Ryan