If you want to produce a HTML version of your documentation with LATEX2HTML you have to copy the file '.latex2html-init' from the 'latex2html/' directory into your home directory. If you already have your own '.latex2html-init' just insert the marked lines of the provided file into yours. Especially pay attention that the $TEXINPUTS variable holds the paths to which you copied the ProgDoc style file 'progdoc.sty'.