FPM - Get Parameter ID via Call Transaction

Hi All,

I am using the following code to call MIR7.

*--- Build the Transaction Fields
      ls_trans_fields-header_text = 'Create Invoice'.
      ls_trans_fields-tcode = 'MIR7'.
      ls_trans_fields-gui_type = 'WIN_GUI'.

      CONCATENATE sy-sysid 'CLNT' sy-mandt INTO ls_trans_fields-system_alias.

      APPEND LINES OF lt_application_parameters TO ls_trans_fields-parameter.


*--- Build the Additional Transaction Paramenters
      ls_add_trans_params-navigation_mode = 'EXT_HEAD'.
      ls_add_trans_params-parameter_forwarding = 'G'.
      ls_add_trans_params-history_mode = '1'.
      ls_add_trans_params-skip_init_screen_if_possible = abap_true.

*--- Launch the Application
      CALL METHOD go_fpm_nav_to->launch_transaction
        EXPORTING
          is_transaction_fields    = ls_trans_fields
          is_additional_parameters = ls_add_trans_params
        IMPORTING
          et_messages              = lt_mess
          ev_error                 = lv_error.

This code works great to call MIR7; however, unlike the tradition SAP GUI, I am not able to get the resulting Invoice Number (RBN Parameter).

The sample code below works great to call MIR7 in the traditional GUI and get the resulting Invoice number with the GET PARAMETER ID statement.

  DATA: lv_invoice TYPE belnr_d.
  CALL TRANSACTION 'MIR7'.
  GET PARAMETER ID 'RBN' FIELD lv_invoice.

Is there a way to capture this Invoice Number in a similar fashion in FPM?  Thanks.

John