For web scenarios PD4ML JSP taglib offers a tag to pre-process such type of paths, however it makes nothing special: it looks for a given pattern (for example,
"\"/userdata/includes") and substitutes it with a desired string (
"\"userdata/includes") . It works with the source HTML document as with a single string, ignoring the document structure - you could always implement your own similar solution.
But I would recommend you to create a simple custom resource loader:
post43.htmland to interpret the "non-standard" paths the way you like.