Do you know, that the right window holds HTML? You can write there whatever HTML code you want. Just switch to HTML view..
This might be an excellent use for the See Also feature. Basically, you open the See Also pod and define a See Also keyword. Perhaps DTMUtils. Then you would associate all the topics in the folder with the keyword. Then when you want to present a list of items inside the folder, you insert a See Also control that points to the keyword. After generating, the user clicks the See Also button (or link or whatever) and up pops a list of the HTML pages in that folder.