An extended version of BROWSE_FOR_FOLDER@.
INSTR is an input string that appears in the dialog box as instructions to the
user. PATH is an output string that gives the full path of the folder selected
by the user. If a valid folder is not selected or the user clicks on the CANCEL
button, PATH is returned as an empty string and the function returns .FALSE..
You can provide an initial PATH, that is automatically selected when the
dialog is opened, by making a prior call to the subroutine
HWND can be set to zero or to the Windows handle of the parent window.
FLAGS can be used to customise the appearance of the dialog box.
Passing z'40' allows for features like folder creation. A full list of the flags is available in
the documentation for the ulFlags member of the BROWSEINFO structure.