How to turn a string with a valid Erlang expression into an abstract syntax tree (AST)?

I would like to convert a string containing a valid Erlang expression to its abstract syntax tree representation, without any success so far.

Below is an example of what I would like to do. After compiling, alling z:z(). generates module zed, which by calling zed:zed(). returns the result of applying lists:reverse on the given list.

-module(z).
-export([z/0]).

z() ->
  ModuleAST = erl_syntax:attribute(erl_syntax:atom(module),
                                   [erl_syntax:atom("zed")]),

  ExportAST = erl_syntax:attribute(erl_syntax:atom(export),
                                   [erl_syntax:list(
                                    [erl_syntax:arity_qualifier(
                                     erl_syntax:atom("zed"),
                                     erl_syntax:integer(0))])]),

  %ListAST = ?(String),  % This is where I would put my AST
  ListAST = erl_syntax:list([erl_syntax:integer(1), erl_syntax:integer(2)]),

  FunctionAST = erl_syntax:function(erl_syntax:atom("zed"),
                                    [erl_syntax:clause(
                                     [], none,
                                     [erl_syntax:application(
                                        erl_syntax:atom(lists),
                                        erl_syntax:atom(reverse),
                                        [ListAST]
                    )])]),

  Forms = [erl_syntax:revert(AST) || AST <- [ModuleAST, ExportAST, FunctionAST]],

  case compile:forms(Forms) of
    {ok,ModuleName,Binary}           -> code:load_binary(ModuleName, "z", Binary);
    {ok,ModuleName,Binary,_Warnings} -> code:load_binary(ModuleName, "z", Binary)
  end.

String could be "[1,2,3].", or "begin A=4, B=2+3, [A,B] end.", or anything alike.

(Note that this is just an example of what I would like to do, so evaluating String is not an