What you need to do, is duplicate the frequency, then it will cancel itself out.
For example, if you want to cancel out say 3156khz. You need to record yourself singing a song by the Bay City Rollers in monotone at at 3165khz. Both frequencies will cancel each other out. BUT, this will only work if you sing the Bay city Rollers. don't try singing anything else. This could potentially cause a voltage overload within your DAW, causing rabbits to jump out of both the input and output sockets of your interface.
Now, this won't entitely cancel out the frequency, what you will need to do is run it all through a step filter followed by Har-Bal. This in turn will only work if you are eating a cream bun at the time. Next, run it all through Windows Movie Maker, whilst reaching down a well and tickling a midget whilst recording it all witha microphone. The combination of you singing the Bay City Rollers in monotone, the stepfilter and Har-Bal, and the midget going "Tee Hee" with completely cancel out the unwanted frequency.
Thisis one of the most notoriously difficult recording tricks to pull off. Rumor has it that Warren Spector almost did it, and would have been in line for a nobel prize had he done so. Unfortunately he was using a cheap chinese mic at the time, causing a black hole to open and swallow half his studio, which later appeared in Guatamala. He got closer to pulling it off the next time,when he discovered that using a marshmallow as an attenuator between his home made nuclear reactor and his preamp stopped the "bunnny rabbit" issue. This is how he accidentally happened upon his famous "wall of sound", and the rest is history.
Bottom line is, you need to be in a near perfect mixing environment to pull this off. Which inevitably means that, if you don't already have one, you will need to buy a lava lamp.