Modify Variant mantaining some values

Hi,

I want to modify some fields of a variant used in a submit while keeping the rest of the fields unchanged. I've tried to use the FM SUBST_WRITE_UPGRADE_VARIANT but I only can indicate the fields that I want to change because the program calls different programs, each with a variant of their own.

Basically, I want to loop 12 times (one for each month of the year) and for each loop, set the variant with the corresponding month.

DO 12 TIMES.

...

t_parametros-selname = itab-period.

t_parametros-kind = itab-tipo_perio.

t_parametros-sign = 'I'.

t_parametros-option = 'EQ'.

t_parametros-low = v_month.

t_parametros-high = v_month.

APPEND t_parametros.

CLEAR t_parametros.

...

CALL FUNCTION 'SUBST_WRITE_UPGRADE_VARIANT'

EXPORTING

iv_reportname = itab-program_name

iv_variantname = itab-var_name

iv_varianttext = var_string

• IMPORTING

• EV_FUNCRC =

TABLES

tt_reportparam = t_parametros

...

SUBMIT (itab-program_name) TO SAP-SPOOL

SPOOL PARAMETERS params

WITHOUT SPOOL DYNPRO

VIA JOB jobname NUMBER jobcount

USING SELECTION-SET itab-var_name

AND RETURN.

...

Thanks!