TAPI linedrop problem

Hi, I have a problem with Tapi.
I have to check a telephone line that is used by another App.
The problem is that I do not find a way to drop calls of this App.

TAPI SDK:
-----
LONG lineDrop(
HCALL hCall,
LPCSTR lpsUserUserInfo,
DWORD dwSize
);

hCall
A handle to the call to be dropped. The application must be an owner of the call. The call state of hCall can be any state except idle
------

So I am not the "owner" of the calls!!
HOW COULD I SOLVE THIS PROBLEM?????
IS IT POSSIBLE????

(I have never worked with Tapi before....please help me!)