You mistyped varibale name, '&Alias' instead of '&cAlias' . Anyway, you don't need macro substitution in this case.

IF oldval( "MYFIELD", cAlias ) == EVAL(cAlias + ".MYFIELD")

>Could someone tell me why I get error "missing operand" in the following code:
>
>

>cAlias = "MYALIAS"
>IF oldval( "MYFIELD", cAlias ) == &Alias..MYFIELD   && Error!
>

>