Hey,
I think that a formant is just a group of several frequency regions at predefined amplitudes which sound like vowels.
You can make an 'eeee' sound in Cool Edit by generating 3 sine waves at 270hz/0dB, 2300hz/-15dB, and 3000hz/-9dB and mixing them together (make sure the file is a 32 bit file, then normalize to 98% before listening).
In theory, if I had three tin whistles or flutes which could play the notes C#4, D7 and F#7 (not exactly, but close enough), you would also be able to make a similar sound.
Do I win a date with Borat?
Nick