Hi
GF, My suggestion was just to enable an estimate the error difference between GPS WGS - 84 & the Russian co-ordinates for the departure way points - not to apply any bias.
Boroda, If there are no ground aids, then all I can suggest is to check the FMGC tracks and distances to your departure way points, and compare them with the published figures. When you are at the holding point, check the track and distance to your first way point (against the published data), and if it all agrees to within the accepted tolerance (e.g. <1 nm for PRNAV) then the two co-ordinate systems are close enough.