This is reference to the following manual, GAF T.O. 1F-MIG29-1, so might not be accurate to the version we get.
Page 1-110 refers to "reference coordinates" which are deducted from the waypoint coordinates as part of generating a code that is entered into the Nav Comp. Anyone know what these "reference coordinates" are?
Putting aside the formulae used following the result of the above calculation, then add a couple of prefixes from the table 1-62B, this doesn't look like something that would be done in flight.
I assume the Russian version doesn't have TACAN and this is only in the German version?