Can I iframe a "layered" https page on an http site? Options

[avd]

I'm trying to show pages from an https site on a page on this organization's http site.
Host page is: http://hohokuscommunitychurch.org/vbs.aspx#
Target: https://www.groupvbs.com/webtoybox/myvbs/hhkcommunitychurch

The problem is the target url is "layered" and the last "hhkcommunitychurch" acts like a password to open this page, because the host organization has many accounts and needs a way to define which account's page to open:
https://www.groupvbs.com/webtoybox/mysite/default.aspx

Currently I have it set to redirect to the target page in a new window, but I'd prefer to iframe it and keep visitor's on our site.
Oddly, if I add the target site to "trusted sites" and then remove it, it works fine. But on a computer where I haven't added it, the iframed page won't load.