I tries to give code exactly like yours, but still not working.
Code snippet is this:
ls_nametab-fieldname = 'PARTNER_NO'.
append ls_nametab to lt_nametab.
ls_nametab-fieldname = 'PARTNER_FCT'.
append ls_nametab to lt_nametab.
LS_PARTNER_COM-REF_PARTNER_FCT = '00000014'.
LS_PARTNER_COM-REF_PARTNER_NO = V_PARTNER.
APPEND LS_PARTNER_COM TO LT_PARTNER_COM.
WA_INPUT_FIELDS-FIELD_NAMES[] = lt_nametab[].
INSERT wa_input_fields INTO TABLE lt_input_fields.
CALL FUNCTION 'CRM_PARTNER_MAINTAIN_SINGLE_OW'
EXPORTING
iv_ref_guid = ls_header_guid
* iv_ref_kind = l_c_ref_kind
is_partner_com = ls_partner_com
CHANGING
ct_input_field_names = lt_input_fields
EXCEPTIONS
error_occurred = 1
OTHERS = 2.