rrrrg... I mistyped the first examples, they should read:
(%i1) mta(expr,v) := ? ?makelist(expr,inpart(v,1),1,inpart(v,2))$
(%i2) mtb(expr,v) := create_list(expr,inpart(v,1),1,inpart(v,2))$
(%i3) mtc(expr,v) := apply('create_list, [expr,inpart(v,1),1,inpart(v,2)]);
(%i4) mta(x,[x,2]);
(%o4) [x,x]
(%i5) mtb(x,[x,2]);
(($INPART) $V 1) not a symbol
#0: mtb(expr=x,v=[x,2])
?-- an error. ?To debug this try debugmode(true);
(%i6) mtc(x,[x,2]);
(%o6) [1,2]
John