Searching files for a file format

Is there a way to search a drive's files only for a specific file format, then display them to the user (and stored somewhere to be used later)? Maybe with the Shell, but I don't know how to use it very well.

At the moment, I have a dropdown to select a drive, a text entry field for the user to enter the extension, a "Search" button to actually search for the files, and a file list box to show the files using the extention (hopefully).

Is there a way to do this in VB6?