Acrobat Pro XI: Customizable file picker dialog?

In Acrobat XI Javascript, is it possible to give a file-picker dialog a custom heading or some other custom text to give it a context? My app, which is folder-level and accessed via a custom menu item, requires users to pick two existing PDF files, pages of which will be interleaved in a specific way to produce one new PDF file. I would like users to know whether they are picking file #1 or file #2.

One clunky way to do this boils down to the following:

1. alert("Pick File #1"),
2. browseForDoc to get file #1
3. alert("Pick File #2"),
4. browseForDoc to get file #2

Is there another way to do this, short of a full-blown custom dialog box?