calling COM method

[Guest]

I created a COM DLL uisng vc++ that installed in client side which capture
the desktop screen, i converted the stream of bytes as one string to have it
in
char *

the COM Method is

STDMETHODIMP CCaptureDT::get_GetScreen(CHAR* pVal)
{
// TODO: Add your implementation code here
*pVal = GetScree();
return S_OK;
}

My Questions:
1. How can i register the DLL automatically as soon as i installed it in
client machine
2. How can I call this function from asp.net client side.