Multicolumn: justify left and fill unused space from the left. (Odd pages.)

Question

Esteemed community, I have a two column document layout, and am aware that normally I can choose between

1. justifying text to the left, which fills unused space from the right, and
2. justifying text to the right, which fills unused space from the right.

How can I get alignment that justifies text to the left, but places the entire box of text as far to the right in the column as possible according to the longest line, thus filling unused space from the left?

The solution should affect whole columns on odd-numbered pages (should be definable centrally), and I don't know the width of the text beforehand, this may be different for every column.

Many thanks for your input.

Answer 1

^{Click on the images to see it in a better resolution}

Edit 1: Odd/even page check added

\documentclass{article}
\usepackage[showframe]{geometry}
\usepackage{lipsum}
\usepackage{array}
\usepackage{varwidth}
\usepackage{changepage}
\strictpagecheck
\def\maxwidth{13cm}
\newcolumntype{M}{>{\begin{varwidth}{\maxwidth}}l<{\end{varwidth}}}
\newenvironment{myenvi}
    {%
        \checkoddpage
        \ifoddpage
            \hfill\begin{tabular}{@{}M@{}}
        \fi
    }
    {%
        \checkoddpage
        \ifoddpage
            \end{tabular}\hspace{-3.5pt}
        \fi
    }

\setlength{\parskip}{1ex}
\begin{document}
\lipsum[1]

\begin{myenvi}
Oh, this is what I want!

I really want some lines like this

And this line is a bit too long, so it will be broken to some lines blah blah. And this line is a bit too long, so it will be broken to some lines. And this line is a bit too long, so it will be broken to some lines. And this line is a bit too long, so it will be broken to some lines.
\end{myenvi}

And some more normal lines

\begin{myenvi}
This is a short text for testing whose total width is clearly less than 10cm.

And this is an even shorter text.
\end{myenvi}

\lipsum[2-6]

\begin{myenvi}
This is the environment for check in an even page. It should be like normal text.

Yes, this is normal text!
\end{myenvi}

\lipsum[7]
\end{document}

Page 1 (odd):

Page 2 (even):

Original answer

Define a new tabular column type and use \hfill

\documentclass{article}
\usepackage{lipsum}
\usepackage{array}
\usepackage{varwidth}
\newcolumntype{M}{>{\begin{varwidth}{10cm}}l<{\end{varwidth}}}

\setlength{\parskip}{1ex}
\begin{document}
\lipsum[1]

\hfill\begin{tabular}{@{}M@{}}
Oh, this is what I want!

I really want some lines like this

And this line is a bit too long, so it will be broken to some lines blah blah. And this line is a bit too long, so it will be broken to some lines. And this line is a bit too long, so it will be broken to some lines. And this line is a bit too long, so it will be broken to some lines.
\end{tabular}

\lipsum[2]
\end{document}