[Tex/LaTex] Multiple authors, with multiple affiliations

Question

I have a paper with 3 authors, affiliated to 3 institutions, and it's supposed to abide to the IEEEtran format.

Author A is affiliated to X and Z, Author B is affiliated to X, and Author C is affiliated to Y.

I wonder if (and how) I can organize the author section like:

As you can see, Author 1 has multiple affiliations. I guess I could have a completely separate column for each author, with his affiliation below, but Author 1 would then have 4 lines of affiliation…

The code I currently have is:

\documentclass[10pt, conference, compsocconf, letterpaper]{IEEEtran}

\pagestyle{plain}

\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{graphicx}
\usepackage{color}
\usepackage{amssymb}
\usepackage[draft]{fixme}
\usepackage{soul}

\begin{document}

\title{Paper Title}

\author{
    \IEEEauthorblockN{Author 1}
    \IEEEauthorblockA  {
        University X\\
        Country of X\\
        University Z\\
        Country of Z
    }
    \and
    \IEEEauthorblockN{Author 2}
    \IEEEauthorblockA  {
        University X\\
        Country of X
    }
    \and
    \IEEEauthorblockN{Author 3}
    \IEEEauthorblockA  {
        University Y\\
        Country of Y
    }
}

\maketitle

\end{document}

Answer 1

You can (ab)use the \title field:

\documentclass[10pt, conference, compsocconf, letterpaper]{IEEEtran}

\pagestyle{plain}
\newcommand\Mark[1]{\textsuperscript{#1}}

\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{graphicx}
\usepackage{color}
\usepackage{amssymb}
\usepackage[draft]{fixme}
\usepackage{soul}

\begin{document}

\title{Paper Title\\[.75ex] 
  {\normalfont\large 
    Author 1\Mark{x,z}, Author 1\Mark{y}, Author 3\Mark{z}%
  }\\[-1.5ex]
}

\author{
    \IEEEauthorblockA{%
        \Mark{x}University X\\
        Country of X%
    }
    \and
    \IEEEauthorblockA{%
        \Mark{y}University Y\\
        Country of Y%
    }
    \and
    \IEEEauthorblockA{%
        \Mark{z}University Z\\
        Country of Z%
    }
}

\maketitle

\end{document}

If you are writing for a journal, this decission will be discarded anyway.