Hi Derek,
It is a little confusing what is where in this scenario. You have two seperate JavaScripts here, one for the VWG application and one for the AspPageBox page.
If I understand you correctly, you have an Html box in the VWG application, and you want from the client side JavaScript of the aspx page do an update of the client side value of the HtmlBox of the VWG application.
Is this what you are asking? If not, please explain in more detail, and preferably build a small sample application to demonstrate what you are trying to do, maybe with a simple VWG form with an AspPageBox including a simple aspx page where you show us what you want to do.
Palli