String manipulation

From Sapwiki

 lv_string = 'Hallo mein Name ist...'.
 write lv_string+2(4).

     2   4
     v   v
 " 'Hallo mein Name ist...' - > 'llo '

 CONCATENATE ls_booking_data-time_from(2) ':' ls_booking_data-time_from+2(2) ' - ' 
 
 ls_booking_data-time_to(2) ':' ls_booking_data-time_to+2(2) INTO ls_values-value.