\documentclass[parskip,paper=a4,pagesize,DIV13]{scrartcl}
\usepackage{tabularx}
\pagestyle{empty}

\makeatletter
\newcommand*{\itemlabel}[2]{%
  \item[{#1}]%
  \leavevmode
  \rlap{% Setze Anker fuer hyperref
    \raisebox{.7\baselineskip}[0pt]{%
      \kern-\leftmargin\csname phantomsection\endcsname
    }%
  }%
  \protected@edef\@currentlabel{#1}% Setze Inhalt fuer Label
  \label{#2}%
  \ignorespaces
}
\makeatother

\usepackage{hyperref}

\begin{document}
\begin{tabularx}{\textwidth}{XX}
\begin{enumerate}
\item \label{first}First
\item[(foo)]\label{foo}Foo
\item \label{last}Last
\end{enumerate}

\ref{first}, \ref{foo}, \ref{last}
&
\begin{enumerate}
\item \label{first2}First
\itemlabel{(foo)}{foo2}Foo
\item \label{last2}Last
\end{enumerate}

\ref{first2}, \ref{foo2}, \ref{last2}
\end{tabularx}
\end{document}

