Setting selection condition on markets without prefixes

Hi,
Anyone can tell me how I can set this?
Example:
market is Half Time Score(market without prefix)
How to set: Selection 2(score 1:1) back price is >2
I tried: Selection's  Trigger Expression  Half_Time_Score_s_2_back_price  is greater then 2
but it seems that this not going to work
On Correct score market I use football2_s_2_back_price is greater then 2, and it seems that this expression is correct.
Thanks.

Anyone? Please 

No, that is not case. I want to place some bets on Half time score market, but I don't know how to set conditions on this market type.
How to set this condition on Half Time Score market:  Selection 2 (score 1:1 in this case) back price is >2

Shouldn't it be .... football5_s_2_back_price ?

I think not. Football5 is prefix for Half Time(winner) market, not for Half Time Score market.

...why not use to conditions

selection's index=2
and back_price>2

I need to set a couple conditions for different selections at same time, then this will not work I think.

sorry seems to complex for me, (football18_  is the HT score?).

Where did you find football18 prefix? I saw prefixes up to 17 for football.

"football18_
This prefix refers to a Half Time Score market in a Football match, if checked within the other markets of the same match."

from the Manual!

http://marketfeeder.co.uk/download/MF8_manual_eng.pdf

Hi tupp,
it seems you are right, I overlooked that because I looked through manual about 2 months ago and forget all prefixes written there. I looked directly in program and didn't find that prefix already entered by default(you can see attachment). You can see 17 prefixes for football on picture which are entered by default. But I will test with football_18 prefix to check this.
Thank you for your help, much appreciated.