[??] same architecture, many builds, where DOC?

I cannot be the first person who has faced this issue. Here at work, we have many different versions of XEmacs, each for the same architecture. One with-mule, another with-sparcworks, and another with-external-widget. What we would like to do is have all of these executables in the same install directory with different names. However, the problem is that they each have an executable-specific DOC file. I know that there is a variable `internal-doc-file-name', which defaults to "DOC". Can I just do a setq in site-start.el, or is there a better way? Example: (setq internal-doc-file-name (concat internal-doc-file-name (and (featurep 'mule) "-mule") (and (featurep 'external-widget) "-ew") (and (featurep 'sunpro) "-sun"))) This seems a little hackish, but I really don't want to have a different exec-directory for each of the different versions on the same architecture. It just seems ugly. Does anyone have any thoughts on this? Thanks a lot. -- Colin