One approach could be based on:
.PP
.RS 5
-msgs=`inc -format '%(msg)'` && [ -n "$msgs" ] && scan $msgs && \
+msgs=\`inc -format '%(msg)'\` && [ -n "$msgs" ] && scan $msgs && \
mhfixmsg -nochangecur $msgs
.RE
.PP
.ta \w'\-fixboundary 'u
PATH = %bindir%:$PATH
LANG = en_US.utf8
-MAILDIR = `mhparam path`
+MAILDIR = \`mhparam path\`
#### The Backups directory is relative to MAILDIR.
MKSTEMP = 'mkstemp -directory Backups -prefix mhfixmsg'
MHFIXMSG = 'mhfixmsg -noverbose -file - -outfile -'
:0 w: nmh-workers/procmail.$LOCKEXT
* ^TOnmh-workers@nongnu.org
-| tee `$MKSTEMP` | $MHFIXMSG | $STORE +nmh-workers
+| tee \`$MKSTEMP\` | $MHFIXMSG | $STORE +nmh-workers
.fi
.RE
.SH "EXAMPLES"
.PP
.RS
.nf
-for msg in `pick +folder`; do mhfixmsg +folder $msg; done
+for msg in \`pick +folder\`; do mhfixmsg +folder $msg; done
.fi
.RE
.PP