ook like backslash substitutions for Tcl commands are replaced by
their corresponding character.
<P>
When the <B>TCL_SUBST_VARIABLES</B> bit is set in <I>flags</I>,
sequences that look like variable substitutions for Tcl commands are
replaced by the contents of the named variable.
<P>
When the <B>TCL_SUBST_COMMANDS</B> bit is set in <I>flags</I>, sequences
that look like command substitutions for Tcl commands are replaced by
the result of evaluating that script.  Where an uncaught
&#8220;continue exception&