Yes, that's certainly possible, and could provide for a nasty surprise attack that could not be detected until late in the engagement.  It would have the most potential against non-manuevering targets like AWACS, tankers, and C4ISR aircraft.  Once again, there's little reason to think a stealth aircraft will even be detected/tracked via passive detection equipment like Kolchuga, and even versus "normal" jet fighters the positional accuracy is going to be gross and not reliable to always guide a SAM to a position where its active radar could lock on--especially not against a stealth target, since the LO would reduce the range of the missile's radar.  However, it does seem your idea could work well against predictable targets like an HVAA in a known orbit.  It's an idea very similar to how the Chinese apparently plan to control their FT-2000 anti-radiation SAM.