Hi,
Numc fields can be concatenated.
Have a look at http://scn.sap.com/docs/DOC-47512 and the program included :
*----------------------------------------------------------------------*
TYPES: BEGIN OF tp_vald_1 .
* Note the RENAMING WITH SUFFIX .
INCLUDE TYPE tp_ent_xxx AS ent_001 RENAMING WITH SUFFIX _ent_001 .
INCLUDE TYPE tp_ent_xxx AS ent_002 RENAMING WITH SUFFIX _ent_002 .
INCLUDE TYPE tp_ent_xxx AS ent_003 RENAMING WITH SUFFIX _ent_003 .
INCLUDE TYPE tp_ent_xxx AS ent_004 RENAMING WITH SUFFIX _ent_004 .
INCLUDE TYPE tp_ent_xxx AS ent_005 RENAMING WITH SUFFIX _ent_005 .
INCLUDE TYPE tp_ent_xxx AS ent_006 RENAMING WITH SUFFIX _ent_006 .
INCLUDE TYPE tp_ent_xxx AS ent_007 RENAMING WITH SUFFIX _ent_007 .
INCLUDE TYPE tp_ent_xxx AS ent_008 RENAMING WITH SUFFIX _ent_008 .
INCLUDE TYPE tp_ent_xxx AS ent_009 RENAMING WITH SUFFIX _ent_009 .
INCLUDE TYPE tp_ent_xxx AS ent_010 RENAMING WITH SUFFIX _ent_010 .
INCLUDE TYPE tp_ent_xxx AS ent_011 RENAMING WITH SUFFIX _ent_011 .
INCLUDE TYPE tp_ent_xxx AS ent_012 RENAMING WITH SUFFIX _ent_012 .
INCLUDE TYPE tp_ent_xxx AS ent_013 RENAMING WITH SUFFIX _ent_013 .
col_pos TYPE n LENGTH 3 ,
CONCATENATE 'ENT_' <st_alv_hdrc_1>-col_pos INTO fieldname .
* Get specific week entry
ASSIGN COMPONENT fieldname OF STRUCTURE st_bffr_8 TO <st_ent_xxx> .
<st_ent_xxx>-paymentsum = <st_sflight>-paymentsum .
Regards .