I'm not sure how I would go about it, if in any way different from what has already been suggested. But however it is to be accomplished, there are questions.
What would the User process be? Select a path object to copy along, and select the object? Or objects? [That is, could your triangle be three Lines?] Specify something as the object that isn't already there to select, such as a Block name, and Insert that as part of the process? Be asked to draw something instead of select something? Then what? Pick a starting reference point along the path? Or use the nearest point along the path as the starting reference? Nearest to what on the selected object(s)? And in what form would the varying distances be supplied? Ask the User for each spacing as it goes along? Pull them from something like a list variable or a .csv or .txt file? Specify at least the first copy location on the path itself [not just as a distance number], so the routine knows whether to work in the path's drawn direction or the other way? Etc., etc.
Kent Cooper, AIA