How can I merge many Excel files automatically?

We have around 350 Excel files.
Each of these is named Something(Stock).xls
Each has a number of tabs e.g. Stock and Sold
The column formatting is identical in all files.

I want to merge all the stock tabs from all the files into 1 excel file.

Is there a way I can do this with some sort of scripting or program rather than doing it manually?

Thanks