ACCESS TreeView Icons

Have an existing Access Form with Treeview control that lists folders & sub folders and any files within them, starting with our defined root folder. . Would like to change node icons based on whether it is a folder or file. And when a file by the type of file. We have 5 main kinds of files to be found within these folders & sub folders. .xls .vsd .pdf. and images (jpg / bmp/ png) Any files outside those can have a generic icon. (Txt perhaps) I have added icons to imagelist control but I need help to determine file type and reelect that. In a nutshell I need treeview to display icons representing folders, xls,vsd, pdf and image files.