Well, I finally got around to trying out the scripting you presented and I have similar issues to what I was already having.
component.DamageType & (DamageRes.dtCold|DamageRes.dtFire|DamageRes.dtLig htnin|DamageRes.dtPoison)
That gives my a list of everything, probably includign what I want if I could find it.
component.DamageType
This me no options at all.
I also tried: component.DamageRes and got nothing.
When you have a moment or two, could you try create an Adjustment and see what you get. Maybe my HL is messed up . . .