Strategy Tester - virtual chart not active chart?

Im writing an EA here that takes values from compiled indicators that i do not have the source for.

So i attempt to use iCustom and WindowPriceMax and WindowPriceMin to "scrape" values from these indicators.

Now i cant actually test my EA live today as the markets are closed so im using the strategy tester. But it doesnt seem to load my compiled indicators. Im using the WindowScreenshot function and WindowFind functions to see if my compiled indicators are actually loaded and the screenshots returned are just normal bar charts without any of my specialiased indies and the WindowFind just returns -1 which means it cant find my indies!

This thread here :

Problems with new Expert Advisor in MQL4 - Forex Trading Software Forum

Seems to suggest that the strategy tester uses a "virtual chart" and not the actual loaded chart.

This does fit with the little bit of live testing i did last night when the markets were open as the screenshots returned then were the shots of my real indies.

the indie itself it pretty simple, just a moving average but it does *something* special that i cant fully replicate. I wont be getting the source for it anytime soon either.

But i do know what buffers it uses and i can extract them using iCustom sucessfully. Im using the WindowPricemin to help me analyse these values i extract.

So the compiled indie is fine if not ideal. I can work with it in live demo's just not in strategy tester, which seems very strange.

It seems to be that i cant load this compiled indie in the stratey tester to allow me to use WindowPriceMin?

So the question is really what chart does the strategy tester use? and how do i get it to use my inides and not this "virtual chart"?

Thanks