Hi
I don't think it's possible to address individual bets globally, but you can do so for a given selection:
selection index 1 last back matched bet price
s_1_bm_1_backp
selection index 1 second last back matched bet time
s_1_bm_2_backtime
selection index 3 second last unmatched back bet amount
s_3_bu_2_backa
etc...