Backing...... with "stop at a loser" before starting from bet 1 again

Is there a way of using the back till you win trigger similar to this one I am testing ......... ((1 + last_lost) / (back_price-1))/(1-commission) ...................but with a limitation on the number of losing bets in a row. I want a maximum of  8 settled losing bets placed,  before  recoupment then ceases. However the trigger should then re commence automatically at stage 1, after the losing 8 bets . Therefore rendering the 8 lost bets permanently lost?

I feel that Loss recoupment (when there is no limitation) can either end up staking more that the amount available to back, or exhaust the bank. 
 
As ever any help with this appreciated.

OK GUYS
I think I have cracked it now. using a series of "hist_count" and "losses" and "total won" and then going to a second trigger with bm_backnum it works OK.

By the way I think I have found the ultimate "lay system". my trigger in the competition which backs horses who have not run for 150 days or more, is by far the biggest loser i am testing.
Early indications were encouraging, however since then i have had NOTHING BUT LOSERS ON THE BACK BETS.
i hope that tomorrows test continues in the same vein, and a blank on the final day  of testing will mean that we can lay these nags in the full knowledge that this time next year we will all be millionaires! I could also have the dubious privilege of by far the worse trigger tested!!