\documentstyle[decalign]{report}

\begin{document}

\begin{tabular}{|r||r@{--}l|p{1.2in}|d,|}   % Separator will be a comma.
\hline
\multicolumn{6}{|c|}{GG\&A Hoofed Stock}
  \\ \hline\hline
&\multicolumn{2}{c|}{Price}& &
\multicolumn{2}{c|}{}              % Must treat the d column as two columns.
\\ \cline{2-3}
\multicolumn{1}{|c||}{Year}
& \multicolumn{1}{l@{\,\vline\,}}{high}
& low & \multicolumn{1}{c|}{Comments} & \multicolumn{2}{c|}{Other}  % here too.
  \\ \hline
1971 & 97 & 245 & Bad year for farmers in the west. & 23,45 \\ \hline
72 & 245 & 245 & Light trading due to a heavy winter. & 435,23 \\ \hline
73 & 245 & 2001 & No gnus was very good gnus this year. & 3,8756 \\ \hline
\end{tabular}

\end{document}

%  There are a few caveats.  The `column' is actually two columns, so one
%  must remember that when using \multicolumn or \cline.  Also, to skip
%  the column, you can't just put an ampersand, because that will only skip
%  one column.  You can't put two ampersands, either, because the separator
%  is automatically included as the first thing in the second column.  You
%  must use \multicolumn{2}.  None of the other column specifiers can be used
%  as separators, and the use of certain characters (&, {, }, #, etc.) will
%  probably produce chaos.  This is not a severe inconvenience, because only
%  periods and commas are likely to be used.  Finally, the `d' specifier
%  makes no sense in the {col} argument of the \multicolumn command, and
%  will in fact wreak havoc there.
