open all files in a folder with fixed number of characters in filename

Hi all, I am fairly new to VBA but keen to learn.

I want to open all the files in a folder whose filename consists of a certain number of characters. The filename will be either 6 or 8 characters long. I have two macros and would like one of them to open all the 6 character filenames and ignore the 8 character ones, while the second macro should only open 8 character filenames. I have found through the forum how to open all files of a given type eg "book1*.xls" but am struggling to be specific on the filename length.

Can anyone advise?

Thanks

Mick