I need help with the knowledge ...

Let's assume I have an idea for a 1024 point filter. I know how th
frequency response should be: all points between 100 and 924 are 0 and al
other 1 (I think this should be a perfect low-pass (or maybe not?). So
know the f.response. Now how to filter my signal? What I think i
following:

1.) IFFT convert the frequency response to impulse response (fro
frequency to time domain);
2.) apply some kind of window (hamming for example) by multiplying all th
points after the IFFT with the formula of the window;
3.) now convolute with the signal I receive in time domain (by multiplyin
and summing all the signal's points from 1024 upwards with every point fro
the filter).
4.) What I received is the filtered signal ...

Is this true?