[texhax] Issues with `^' when inputting manmac

[Rodolfo Medina]

Hi all.

The following simple example:

%%%%%%%%%%%%%%%%%%%%%%%
\input manmac

bla bla

\newwrite\inx

\openout\inx=index

\write\inx{$x^2$}

\closeout\inx

\vfill\eject

\input index

\end
%%%%%%%%%%%%%%%%%%%%%%%

gets error when processed with `tex file'.  In fact, D. Knuth activates and
uses in manmac.tex the character `^' in his indexing macros, that I'm studying
and want to use myself.  Anyone has any idea of how to avoid that error?

Thanks for any help,

Rodolfo