Already some good answers here, but there are a few points I'd like to hit again.
First off, echoing several others, do you actually need to produce power from sunlight and detect the laser with the same PV cell? There are situations where this is indeed necessary, but if this is not the case, you'd be better off using a different sort of photodetector for the laser, as already suggested. In that case, you would probably want to put an optical bandpass filter in front of the detector that rejects all wavelengths except what the laser produces. This will greatly help with the saturation problem @Robherc refers to. Be careful that the passband isn't so narrow that tolerances in the filter and laser cause a mismatch and loss of signal. Perhaps this partially addresses your confusion about the laser wavelength and the 1kHz electrical bandpass filter, which is in an entirely different domain. If you really need to do what you originally described, though, then this isn't an option.
You say you need 'pinpoint accuracy'. That's more of a marketing term than an engineering term. What do you really mean? You're not going to get better spatial resolution than the size of your detector, so again, if spatial accuracy is important, a power generation PV cell is not going to be your detector of choice.
You also say you don't care about intensity or detecting time. You may be thinking that you don't care, but, again, if we're doing engineering here, it's very unlikely that you truly don't care about these things. Are you really OK with 1 attowatt of received power and 100 hours of integration time? In order to design something, you have to start by putting numbers on pretty much everything you know about. Otherwise you have an underconstrained problem that either admits no solution, or allows solutions very different from what you were (possibly unconsciously) expecting.
Oh, and by the way, if you really, really, can't have any false positives (because that launches the missiles, doh!), look out for insects flying in the sunlight that beat their wings at 1kHz.