Leading spaces aren't much of a problem, but aligning comments on the right-side is much harder due to the variable widths of each line. And even if you align them in your editor, they'll be misaligned for people who use fixed-width fonts. Does that make any sense?
Use a word processor (or a text editor that allows for fixed tab stops). This will also allow insertion of diagrams and other non-textual stuff (think clickable buttons, for compilation and testing, for example) into source code.
See, for an example implementation, BlackBox Component Pascal - Windows only, but runs moderately well under Wine.
