[Exim] filter for comparing $h_From:

Quick question. I have a router that performs the function of a
filter; the "data" of which is below:

        data = # Exim filter\n \
          if \
            ${quote:$h_From:} matches "(staff|support|admin|abuse)@$domain" \
          then \
            logfile LOG_PATH/malware \
            logwrite ${quote:$tod_log $message_id malware_bagle: $h_From:} \
            save /dev/null \
          endif

For From: header addresses that contain a '$' character, I get this
error:

    R=malware_bagle defer (-17): error in filter data: failed
    to expand "CarInfo <$Help@???>" in filter file:
    unknown variable name "Help"

Should I use ${rxquote:} instead to avoid the expansion of "variables"
that are inserted into the body of a message by a connecting MTA?

thanks,
hank