Try this little (EEL) script:
Code:
t_n = CountSelectedTracks(0);
i = 0;
while (i < t_n)
(
t = GetSelectedTrack(0, i);
pos = TrackFX_AddByName(t, "volume_pan", false, 1);
GetTrackUIVolPan(t, t_vol, t_pan);
t_vol_dB = 20*log10(t_vol);
TrackFX_SetParam(t, pos , 0, t_vol_dB);
SetMediaTrackInfo_Value(t, "D_VOL",1);
i += 1;
);