Windows (apodization functions) with Nyquist (the language)

I’m trying to remove some annoying beeps from an audio track, and it seems I’m lucky because they’re all pure sinusoids (except for one which has a little third harmonic because it’s clipped). So I can remove them with a simple notch filter, which is provided in Nyquist as “notch2”. The problem is, the beeps are quite short (about 50 milliseconds), so I have to use a fairly low Q for the notch filter in order to completely remove them. But there is other stuff going on in the music, and if I apply the notch2 filter to a short section of audio, it creates audible artifacts when the filter cuts in and cuts out.

So I want to use a window function (something reasonable like a Hamming or Hann window) to make the notch filter gradually take effect and then gradually go away. But I can’t find any window functions in the Nyquist documentation.

Does Nyquist have any built-in window functions, or do I have to write my own?