Forms 6i: How to program to open a dialog box to pick a folder

 I am running Forms 6i.  Is there anything in the pll or anything at all that allows me to open a dialog box and traverse the Directory tree and pick a folder?  The path name from the drive root up to the name of the folder should be returned in a string.  I've only found win_api_dialog.open_file but this one only lets me pick a file while I want the folder name instead.