Browse for excel data files to import

Hello,

I have an Excel application.
My user has many input files (all of them in the same format).
I want to write a moudle which will :

- open a file browser in which the user will select all the data files by once.
- go over the selected files : open each file and copy data to one excel file.

Can you help me or tell me where can I find an example to this task ?
Thank you