Best way to create a wix fragment file based on User-defined directories to be used in MSBUILD

Question

In the spirit of this question by Si here: WiX tricks and tips. I am trying to determine the best way to get create wix fragments based on a directories. File harvesting,

Answer 1

For what it's worth, we are, in fact, using heat.exe from msbuild. If you're as picky as I am, the output of heat is probably not exactly what you want, but this is easy to rectify with an XSL transformation (I believe heat.exe has a command-line parameter expressly for this purpose).