Most of the known pulsars with frequencies lying in the best sensitivity
range of the Virgo/LIGO/TAMA interferometers belong to binary systems.
Accordingly their frequencies are Doppler shifted in an unknown way. We
investigate a new method to search for and extract the parameters of such
pulsars. A first preliminary test of this method, performed on the Virgo data
recorded during the E4 engineering run, is presented