Setting stored value for matched bet

[vetinry]

Another day, another challenge (or probably just stupid question)

Is it possible to set a stored value for the price of a back (or lay) bet, which is placed within an automation file.
I've looked through the automation drop down lists, and can't seem to find one that works.
When I chose "the matched bet of a selection", it doesn't seem to work (returns a zero price in the log)
And when I choose "the price of a selection", it presumably gives me the price around the time that my bet is placed, but is not necessarily the same value. This is working ok but this morning, my back bet was matched at 7 ticks away from the "back" stored value that I created.

I am trying to set a stop loss and trigger which will calculate from the price that I place my back bet at, which is obviously very straightforward in global settings. But I can't work out which of the drop downs will give me that exact starting point ie the price that my initial bet is matched at. And I don't want an offset bet with stop. I have download the servant based file but would like this to run on full auto.

I've read quite a few posts about stored values / signals etc but just seem to locate the one that I want

Help, as always, would be much appreciated.

Thanks

Steve