How to get a form variable inside PerlLogHandler

[Luis Henrique Cassis Fagundes]

        Hi,
        I have a perlloghandler that needs to get a variable from a form to log
the request. To do this, I parse $r->the_request to get the variable
from the query string, but this only works if the method of the form is
GET. Does anyone know how can I do this if the method is POST?
        Thanks.
        []s
        Luis