This code made it work!!! THANKS TOMAS.
DATA: l_i_content TYPE RSRA_T_KWF_CNTBIN,
l_v_xstring TYPE xstring.
FIELD-SYMBOLS: <l_wa_content> TYPE sdokcntbin.
l_v_file = '/tmp/filename.docx'
OPEN DATASET l_v_file FOR OUTPUT IN BINARY MODE.
IF sy-subrc EQ 0.
LOOP AT l_i_content ASSIGNING <l_wa_content>.
l_v_xstring = <l_wa_content>-line.
l_v_len = xstrlen( l_v_xstring ).
l_v_pos = l_v_pos + l_v_len.
IF l_v_pos > l_v_fsize.
l_v_len = l_v_len - ( l_v_pos - l_v_fsize ).
ENDIF.
TRANSFER l_v_xstring TO l_v_file LENGTH l_v_len.
ENDLOOP.
CLOSE DATASET l_v_file.
ENDIF.