[Exim] variables in ACLs

I am trying to implement a score based logic in an RCPT ACL on a recipient or message basis.
Since it looks to me like there are no counters available in ACL, I tried adding a header and then checking for its existence:

warn    message         = X-tagged-1:
    condition       = ${if eq {$local_part}{whatever}{yes}{no}}

deny    condition       = ${if def:h_X-tagged-1:{yes}{no}}
        message         = out

while sending mail to whatever indeed adds the header (as long as it is not received from an authenticated client), the deny condition always fails.

While this particular case does not make sense (I could have just used a deny on its own), if this worked one could check the simultaneous existence of multiple scoring headers.

Is there an alternative? (I'd rather use variables, like counters, as they make score checking much easier).

Thanks

Giuliano
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