Javascript - Get LONG* from COM/ActiveX

Javascript - Get LONG* from COM/ActiveX

I'm using an embedded ActiveX media player which I'm calling from
JS/JQuery. I can call functions and set properties in the player without
issue. However, one of the properties I need from the ActiveX control is a
LONG* pointer, which has the signature....
get_CurrentPlaybackTime_Sec(LONG* pVal)
..and I'm not really sure where to start. I've done some Googling and
found some loose references to BSTR in Javascript, but I'm unsure how to
implement it. I need an equivilent of an 'out' that I use in C# I suppose.
Here is where I am so far...
$("#fooBtn").click(function(){
var currTime;
o.get_CurrentPlaybackTime_Sec(currTime);
$("#fooDiv").text(currTime);
});
Can someone point me in the right direction please? Any help much
appreciated.