[pdftex] Math and bold fonts in pdf bookmarks

[Fred Wong]

Hi all:

I'm new with pdftex and I'm a bit lost in the documentations on pdf
encoding and user macros. Can anyone show me how to generate bookmarks
for the following section headings which contain math and bold fonts: 

\section{Numerical Singularity When $\pi_s=0$} 
\section{Columns of $[{\bf b},{\bf A}_2]$ Linearly Dependent} 

I've searched through the archive and know that I need to use
\textorpdstring{TEXstring}{PDFstring}. However, my TEXstrings contain
characters that seem to be outside the list of supported PD1 encoded
equivalents (found in pd1enc.def). I've also tried turning on the
Unicode option for the hyperref package, and it doesn't seem to work. I
think I may need to use \pdfstringdef to make some new definitions, but
not sure exactly how. 

Many thanks. 

Fred Wong