Determination of the table structure dynamically

TYPE-POOLS: slis.
DATA: it_fcat TYPE slis_t_fieldcat_alv,
is_fcat LIKE LINE OF it_fcat.
DATA: it_fieldcat TYPE lvc_t_fcat,
is_fieldcat LIKE LINE OF it_fieldcat.
DATA: new_table TYPE REF TO data.
DATA: new_line TYPE REF TO data.
FIELD-SYMBOLS: TYPE ANY TABLE,
TYPE ANY,
TYPE ANY.
*Build fieldcat
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
EXPORTING
i_structure_name = 'SYST'
CHANGING
ct_fieldcat = it_fcat[].
LOOP AT it_fcat INTO is_fcat WHERE NOT reptext_ddic IS INITIAL.
MOVE-CORRESPONDING is_fcat TO is_fieldcat.
is_fieldcat-fieldname = is_fcat-fieldname.
is_fieldcat-ref_field = is_fcat-fieldname.
is_fieldcat-ref_table = is_fcat-ref_tabname.
APPEND is_fieldcat TO it_fieldcat.
ENDLOOP.

*Create a new Table
CALL METHOD cl_alv_table_create=>create_dynamic_table
EXPORTING
it_fieldcatalog = it_fieldcat
IMPORTING
ep_table = new_table.

*Create a new Line with the same structure of the table.
ASSIGN new_table->* TO .
CREATE DATA new_line LIKE LINE OF .
ASSIGN new_line->* TO .

*Test it...
DO 30 TIMES.
ASSIGN COMPONENT 'SUBRC' OF STRUCTURE TO .
= sy-index.
INSERT INTO TABLE .
ENDDO.

LOOP AT ASSIGNING .
ASSIGN COMPONENT 'SUBRC' OF STRUCTURE TO .
WRITE .
ENDLOOP.