HANDLE hThreadId = XXXXX;
PVOID pEThread = NULL;
HANDLE hThread = NULL;
PsLookupThreadByThreadId( ThreadId, &pEThread );
ObOpenObjectByPointer( pEThread, OBJ_KERNEL_HANDLE, NULL, NULL, **PsThreadType, KernelMode, &hThread );
ObDereferenceObject( pEThread );