Centering table cells about decimal point with bold and asterisk, for dynamically generated tables

Question

I am using PdfLaTeX (MiKTeX) called via R-Brew to dynamically populate and generate a LaTeX table. Use of R tables does not support all of the statistics, and is not flexible enough for the tables I need, hence the R>Brew>Sweave>LaTeX procedure. Everything works well, except I would like to have the numbers centered around the decimal point.

This is complicated by:

1. significant p-values (<0.05) need to be bolded followed by an asterisk,
2. significant p-values (<0.01) need to include a less-than "<" sign in front of them, the number bolded, and followed by an asterisk, and
3. the p-values are unknown until after compile (dynamically populated).

This example table is what I have working now, and does not include centering the numbers about the decimal. I included the p-values in this table, but keep in mind the p-values are not actually there until compilation. There are too many tables to manually sift through, and they are much larger than the examples below.

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{float}
\usepackage{booktabs}
\usepackage[labelfont=bf]{caption}
\captionsetup[table]{labelsep=space,
         justification=raggedright, singlelinecheck=off}
\usepackage{chngpage}
\usepackage{amsmath}
\usepackage{fp}
\begin{document}
\newcommand\pval[1]{
    \FPifgt{#1}{0.009}
        \FPiflt{#1}{0.05}
            \textbf{#1}\text{*}%
        \else
            \FPiflt{#1}{0.01}
                \textless\textbf{0.01}\text{*}%
            \else
                #1%
        \fi
}
\begin{table}[tbp]
\centering
\caption{Table: Example table.}
\label{tab:my-table}
\begin{tabular}{@{}crccc@{}}
\toprule
\multicolumn{1}{c}{Case} & \multicolumn{1}{c}{Statistic} & \multicolumn{1}{c}{Run\_1} & \multicolumn{1}{c}{Run\_2} & \multicolumn{1}{c}{Run\_3} \\ \midrule
A    & Mean                          & 4.53   & 5.67   & 2.46   \\
B    & Mean                          & 5.38   & 5.83   & 3.94   \\
A-B  & p-value                       & \pval{0.01}   & \pval{0.09}   & \pval{0.01}   \\ \bottomrule
\end{tabular}
\end{table}
\end{document}

An example of the table above before values are injected and compilation.

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{float}
\usepackage{booktabs}
\usepackage[labelfont=bf]{caption}
\captionsetup[table]{labelsep=space,
         justification=raggedright, singlelinecheck=off}
\usepackage{chngpage}
\usepackage{amsmath}
\usepackage{fp}
\begin{document}
\newcommand\pval[1]{
    \FPifgt{#1}{0.009}
        \FPiflt{#1}{0.05}
            \textbf{#1}\text{*}%
        \else
            \FPiflt{#1}{0.01}
                \textless\textbf{0.01}\text{*}%
            \else
                #1%
        \fi
}
\begin{table}[tbp]
\centering
\caption{Table: Example table.}
\label{tab:my-table}
\begin{tabular}{@{}crccc@{}}
\toprule
\multicolumn{1}{c}{Case} & \multicolumn{1}{c}{Statistic} & \multicolumn{1}{c}{Run\_1} & \multicolumn{1}{c}{Run\_2} & \multicolumn{1}{c}{Run\_3} \\ \midrule
A    & Mean                          & <%= stat1$A %>   & <%= stat1$B %>   & <%= stat1$C %>   \\
B    & Mean                          & <%= stat2$A %>   & <%= stat2$B %>   & <%= stat2$C %>   \\
A-B  & p-value                       & \pval{<%= stat3$A %>}   & \pval{<%= stat3$B %>}   & \pval{<%= stat3$C %>}   \\ \bottomrule
\end{tabular}
\end{table}
\end{document}

Using dcolumn seems to work the best with what I have tried so far - it does not center the significant p-values correctly though. siunitx throws errors in the log files for every try I have attempted with it.