set hlookat from (external) javascript

It's been a long time since I worked in krpano and I have a problem:
I need to orient a 360 to the magnetic north.
I have a script in the parent page e.g.:
function myLocation(){
console.log('test')
return '30' //deviation from the magnetic north - dummie value
}

If I run this function from my hlookat, it returns/logs nothing
(<view hlookat="js(myLocation())" ...)

I can run it from <scene onstartup="js(myLocation())"
That actually runs the console.log.

I also tried it this way, but to no result:
<script>
embedpano(
{
xml:"tour.xml",
target:"pano",
onready:function(krpano) {
krpano = krpano.get("global");
krpano.set("view.hlookat", 30);
}
}
);
</script>


So, long story short: how do I pass a value to hlookat from the parent-page?

thanks