  Taking advantage of a recent FORS2/VLT spectroscopic sample of Extreme
Horizontal Branch (EHB) stars in $\omega$ Cen, we isolate 38 spectra well
suited for detailed atmospheric studies and determine their fundamental
parameters ($T_{\rm eff}$, log $g$, and log $N$(He)/$N$(H)) using NLTE, metal
line-blanketed models. We find that our targets can be divided into three
groups: 6 stars are hot ($T_{\rm eff}$$\buildrel>\over\sim\ $ 45,000 K) H-rich
subdwarf O stars, 7 stars are typical H-rich sdB stars ($T_{\rm eff}$$
\buildrel<\over\sim\ $35,000 K), and the remaining 25 targets at intermediate
effective temperatures are He-rich (log $N$(He)/$N$(H)$ \buildrel>\over\sim\ $
$-$1.0) subdwarfs. Surprisingly and quite interestingly, these He-rich hot
subdwarfs in $\omega$ Cen cluster in a narrow temperature range ($\sim$35,000 K
to $\sim$40,000 K). We additionally measure the atmospheric carbon abundance
and find a most interesting positive correlation between the carbon and helium
atmospheric abundances. This correlation certainly bears the signature of
diffusion processes - most likely gravitational settling impeded by stellar
winds or internal turbulence - but also constrains possible formation scenarios
proposed for EHB stars in $\omega$ Cen. For the He-rich objects in particular,
the clear link between helium and carbon enhancement points towards a late hot
flasher evolutionary history.
