Field catalog Merge

Hi

I have an internal table which include one DDIC structure and some extra fields.

To craete field catalog for this internal table I am using Reuse_fieldcatalog_mege.

'OBJECT_TAB': Is the internal table name with extra fields in it.

tabname: Is the DDIC structure

CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'

EXPORTING

i_program_name = g_repid

i_internal_tabname = 'OBJECT_TAB'

i_structure_name = tabname

i_client_never_display = ' '

CHANGING

ct_fieldcat = g_fieldcat_tab[]

EXCEPTIONS

inconsistent_interface = 1

program_error = 2

OTHERS = 3.

Now this g_fieldcat_tab[] table contains only fieldcatalog for tabname other fields of internal table 'OBJECT_TAB' is not comming.

can I append those extra fields to g_fieldcat_tab[]?

Provide some sample code.