Duplicate the Registration Form using WebForm module?

We have a unique need in that we have organizations set up to use our site (using Organic Groups), and each organization will start off with one account per group. We want to give them the ability to add users to the site, others from their organization, and would like them to have access to duplicated registration form that will be pre-filled with some of their own profile info (company name, phone number, etc), allowing them to enter the name and email of the new person. This form would essentially be a duplicate of the site registration form, and would work the same way.

I figured I could just create a form using the WebForm module and duplicate the registration form fields, adding in the profile fields and use keys to auto-fill the info for some of those fields. I'm just not sure how I'd get the form to actually create the user in the database and put them into a moderated queue so we can approve them from the Admin group.

Or, is there another way to accomplish this? I know that users who are logged in cannot see the default registration form because they're already logged in. And we don't want to grant access to the the Admin feature.