Graph vocal harmoncs as Bar Graph

I have been asked to create the following tool, and I am in over my head!
Audacity seems to be the closest fit of all the tools that I have been able to find.
I have an “outdated” knowledge of C++, but have been able to download and compile Audacity 2.0.0 with wxWidgets.
Now looking at what I need to “customize” or Add-In to complete the tool.

Windows 7 -SP1 32bit or 64bit (or Windows XP SP3 32bit), Audacity 2.0.0
Soprano sings a sustained Vowel (Ah, Ee, Oo, etc.) Note (C’‘’ 1024 Hz, E’‘’ 1280 Hz, G’‘’ 1536 Hz, Bb’‘’ 1792 Hz, etc.)
Into a MIC (dbx RTA Measurement Microphone) connected to a MIC => USB Converter (Icicle) connected to a laptop USB port
Audacity needs to:

  1. Read USB signal (currently does this)
  2. Perform a FFT (convert from time-based to frequency-base signal) (Is this in Audacity? I see it has under Analyze: Plot Spectrum… Could be what I am looking for.)
  3. Isolate the Harmonics (fundamental & overtones) (How would I do this? Is there a Add-In)
  4. Present as a BAR GRAPH of Harmonics. (see Excel attachment) (How would I do this? Is there a Add-In)

Harmonics is defined as the multiples of the fundamental frequency.
So if the fundamental frequency is 100 Hz, the harmonics will be 200 Hz, 300 Hz, 400 Hz, 500 Hz, and so on.
If the fundamental frequency were 220 Hz, the harmonics would be 440 Hz, 660 Hz, 880 Hz, and so on.
In terms of intervals on the scale, we hear a base tone, its octave (eight notes up), then a note that is a twelfth up, i.e. a perfect fifth above the octave above the starting pitch, then a note two octaves up from the starting pitch, then one that is a major third above that, and on and on.
If the starting pitch (vowel-note) is middle C (C’ 256 Hz), the overtones are C" (512 Hz), G" (768 Hz): C’‘’ (1024 Hz), E’‘’ (1280 Hz), G’‘’ (1536 Hz), Bb’‘’ (1792 Hz), and so on.

Thanks for any help, direction!
Tom W.

A good starting place would be to see what Audacity can do already.
If you export the spectrum as a text file you should then be able to use that data in a spreadsheet or any other type of numerical analysis that you can devise.