Align text and numeric values by decimal in table body using dcolumn

Question

How can I align numeric values in the body of my table by decimal point when some of those values are accompanied by character values? For example, say I wanted to report some standard deviations in a column aligned by decimal point such that each one is enclosed in parentheses. How can I do things like this?

Update Based on answer by David Carlisle

    \begin{table}[h]
    \begin{tabularx}{\textwidth}{lD{.}{.}{7.4}}
    \toprule
    \multicolumn{1}{c}{Test} & \multicolumn{1}{c}{Test 2} \\
    \midrule
    Test & \mathrm{abcde}(1.23)\\
    Test2 & (4.321)\\
    \bottomrule
    \end{tabularx}
    \end{table}

Answer 1

It always helps if you provide a document showing the problem, but basically dcolumn doesn't really mind about extra characters. (12.3) and 12.3 would both be aligned on the . If you use the centre on . form then there is nothing else to do; if you use the form D{.}{.}{3.2} to specify the space before and after the . you just need to specify enough space for the text parts, specified in multiples of the width of a digit.