Combine 2 different files wich an unique indentifier into 1 excel file with a specific layout

I have a source file ( [login to view URL] 1000 records for an example ) wich will be uploaded to a specific company. This company will return a 2nd file with results ( [login to view URL] 50 records for an example ). These both files have 1 unique indentifier and you should combine the [login to view URL] and the [login to view URL] into 1 excel document. The [login to view URL] file is leading, so the 50 records in the [login to view URL] need to be copied / moved / send or what ever to an excel document and adjust and import the additional info from the [login to view URL] to make 1 final file wich can be send again. I will send the files after the bidding has been accepted. To my knowlegde is this very easy to do for someone with the right knowledge. I need this to be finished as soon as possible. The quiker we finished this, the more bonus i can give.