Sequentially retrieve, process, and return all files in a folder, using Mac Excel 2011.

The title pretty well explains what I'd like my macro to do. All my files in a folder have a single worksheet, and they are *.csv files. There are about 500 files in the folder.
I'd like to sequentially (one at a time) open a file, copy the worksheet to a master file, then close the file returning it to the folder. I'd like to do this for each of the about 500 files in a folder.