Insert word, character, or symbol at beginning of all hanging indents in paragraph

Question

In the same vein as this question (and somewhat similar to this question), I am trying to insert anything (e.g. a word, character, or symbol) at the beginning of each wrapped line in a paragraph. However, the thing inserted should not be inserted before the first line of the paragraph. Here is a visual example of what I am aiming to do - where the red box is meant as a placeholder for whatever you want to insert:

Note that this is different than using a list, because the wrapped lines may have the line break in various places (based on things like badness, hyphenation, etc.). The goal is to have the item automatically inserted, regardless of the length of the paragraph.

I am personally using memoir document class and XeLaTex to compile, but hope that the answer to this can use any document class and pdfLaTex, etc.

The final requirement is to do this without an environment surrounding the text. For example, redefining the hanging indent glue to include something else.

A MWE without the symbols is:

\documentclass{memoir}

\usepackage{lipsum}

\begin{document}

\hangindent=4em\lipsum[1]

\end{document}

Question: Is it possible to redefine the glue at the beginning of the automatic line break (when wrapping) to include something like this? If not, is there another way to do so without wrapping the text in an environment (which is how the first question link above deals with it)?

Answer 1

So long as it doesn't have to page break.

\documentclass{memoir}

\usepackage{lipsum}

\begin{document}
\bgroup
\setbox0=\vbox{\hangindent=4em
  \lipsum[1]}%
\dimen0=\ht0
\noindent\rlap{\begin{minipage}[b]{4em}
  \strut
  \loop\ifdim\dimen0 > \baselineskip
    \advance\dimen0 by -\baselineskip
    \newline\null\hfill *
  \repeat
\end{minipage}}\box0
\egroup

\end{document}