What's lost through translating 40K figures into HOTT are all the unique characteristics of each type which creates the diversity of an army like the Eldar. Modifying the HOTT troop types for some of them might be the answer while maintaining HOTT's straightforwardness; probably play around with this.
So, Eldar are a space-faring race heavily imbued with mystical properties. The following is a much simplified description which has got absolutely nothing to do with HOTT:
First there's the Craftworld (tribe, clan, civilisation, whatever), this lot are from Craftworld Alaitoc. I chose that one because of the comparatively simple paint job and the snazzy blue and yellow combination. The Craftworld provides the heavy stuff and the basic grunts which make up an Eldar force.
Next there are what are called Aspect Warriors, basically mercenaries not belonging to any particular Craftworld who provide specialist-type units to anyone willing to pay them.
The odd-man-out in all this is the Avatar who is basically a physical manifestation of an Eldar god so can show up to fight for any of the Craftworlds.
I've classified the troops in HOTT terms as I see it, others may disagree.
Hero in HOTT terms; could be a god but Heroes are more user-friendly 4 Army Points (AP).
Magician General 4 AP.
Shooters six elements @ 2 AP = 12 AP.
Knights, 2x2 AP = 4 AP. These guys really need a different classification. I was thinking a combination of Knights plus Artillery costing 4 AP per element. Cuirassiers perhaps?
Riders, 2x2 AP = 4 AP. Another needing a different classification. I was thinking a combination of Riders plus Shooters costing 3 AP per element. Dragoons perhaps?
Fliers, 3x2 AP = 6 AP.
Artillery, 3 AP.
Blades, 2x2 AP = 4 AP.
Lurker, 1 AP.
The whole lot together:
41 AP, so plenty to choose from to make up a 24 point standard HOTT army.