Column Sums in pgfplotstable

I want to sum the numbers of the last 3 columns in mytable (see below). If all the dates in column A are different, the MWE works fine giving the proper sums (see MWE). But I wish to list Date-1 in only the first row of column A in and leave the remaining rows of column A blank. In this latter situation, the program fails giving an error message: "...an unbalanced number of columns...". Since all the data refers to Date-1 (not Date-2, Date-3, etc), I'd really appreciate a solution. Thanks.

\documentclass{article}
\usepackage{booktabs}
\usepackage{pgfplotstable}

% #1=table name
% #2=first column name
% #3=list of columns to decorate
% Transpose the table, so we can work on rows instead of columns
\pgfplotstabletranspose[colnames from={#2},input colnames to={#2}]{\intermediatetable}{#1}
%
% Sums for each column
\pgfplotstablecreatecol[
create col/assign/.code={%
\def\entry{}
\foreach \i in {#3} {
\ifnum\pgfplotstablerow=\i
\def\colsum{0}
\pgfmathtruncatemacro\maxcolindex{\pgfplotstablecols-1}
\pgfplotsforeachungrouped \col in {1,...,\maxcolindex}{
\pgfmathsetmacro\colsum{\colsum+\thisrowno{\col}}
}
\xdef\entry{\colsum}
\fi
}
\pgfkeyslet{/pgfplots/table/create col/next content}\entry
}
]{Sum}\intermediatetable
%
% Transpose back to the original form
\pgfplotstabletranspose[colnames from=#2, input colnames to=#2]{\statstable}{\intermediatetable}
}
%

\begin{document}

A B C D E F
Date-1   Ken Tod 202  12  0
Date-2      Wood    Haz 317 1 0
Date-3     Front    -   102 10  0
Date-4     Front Haz 145 11  0
}\mytable

\pgfplotstabletypeset[
before row={\toprule
%%       & \multicolumn{3}{c}{Handedness}\\
\cmidrule{2-4}},
after row=\midrule},
every last row/.style={after row=\bottomrule},
columns/A/.style={string type},
columns/B/.style={string type},
columns/C/.style={string type},
columns={A,B, C, D, E, F},
]\statstable

\end{document}
%