Map and convert several xls files to other xls files

[martiendejong]

Hi,

I am searching for a tool that can do the following:
- map a column in a worksheet in one file, to a column in a worksheet in another file.
- append the data from the mapped column to the target column.
- repeat this process for over 20 files.
- preferably with a graphic user interface.

Does any of you know of the existence of such a tool, or of another way to solve this problem?

P.S. The datasets a quite huge.

Best regards, and thanks beforehand for any help.