Welcome!
Draw the note as long as you wish in the Piano Roll view. Or if you want some variation and fluctuation in the sound, record a note as long as you can blow and copy/ paste it (I assume a breath controller produces slightly varying sound?).
SONAR PE 8.5.3, Asus P5B, 2,4 Ghz Dual Core, 4 Gb RAM, GF 7300, EMU 1820, Bluetube Pre - Kontakt4, Ozone, Addictive Drums, PSP Mixpack2, Melda Creative Pack, Melodyne Plugin etc.
The benefit of being a middle aged amateur is the low number of years of frustration ahead of you.