Lambda the Ultimate

I'm implementing an "eval" function in a scripting language... or at least contemplating it.

I can envision the infinite recursion from as simple a thing as the sequence:

set a to "a"
set evalA to eval(a)

if by eval I mean do variable lookup for strings, and the eval is a "deep" eval. Is one always obliged to make the eval a 1-level shallow eval?

Or is eval() generally not a variable-lookup operator? I could provide a separate one, an explicitly shallow evalWithLookup() or something...

are there good alternatives to macros that give similar power, yet somehow manage to integrate with the non-macro language more cleanly than those of lisps? for example, in Clojure you cannot do (apply and [true false]) because and is a macro. i'm sure there are good reasons for things to have ended up as they are, i'm just wondering if there are other reasonable ways to go that would avoid such things without losing too much else?