MRRL enhancement is not work

Hi , all

     When use MRRL to exeute IR , the IR posted date is system date .

I want to assign new posted date , so  I use enhancement MRMH0001 to assign new Posted Date .

but 'it's not work  .

My step is

1. SMOD

2. enhancement : MRMH0001

3. EXIT_SAPLMRMH_001

4. write small pices of code like this

  I_RBKPV-BUDAT = SY-DATUM - 10.
  I_RBKPV-BLDAT = SY-DATUM - 10  .
  MOVE-CORRESPONDING I_RBKPV TO E_RBKPV_ERS_CHANGE .
  E_CHANGE = 'X'.

But  it is no work , the IR date still is system date .

somebody know how to solved this problem ...