Thread: Read in a Folder to a String Array

I wonder how it could be possible using a windows form(C++) and open a folder on the harddrive somewhere and when open this folder, there will be ex: 5 .txt files inside this folder.
When open this folder the names of these 5 .txt files will be red in into a string array.

I know how to use the openFileDialog but wonder how this could be possible to do.
I dont really know the approach to do something like this. What could be the first step.