Hi there,
Well, it is very probably they may know whatever you may have in your platform, specially if it is a winning indicator/strategy, they will know whether you are a winner or not and whether you are trading manually or automated. Being that the case, of course it is possible to hide the implementation, you can build an external DLL or application where all the calculations are made and send the results back to Metatrader.
This is done by allowing DLL importations in your indicator, script or EA. This way the Metatrader platform wont have any idea of how it is getting those signals. The other approacj is very very similar but more complex where you build an external application and communicates to MT4 via Named Pipes to send only the instructions you want it to execute. This second approach allows more privacy, in terms that MT4 does not know anything but only receives the signals to open/close orders.
If you need more details about any of the approaches just send a message.
Regards,
John.