The custom login page that you create could have whatever logic in it that you want.

It doesn't appear to work.  I can enter the username and password and it logs in fine automatically.  However if i try just the username, i get a blank login form.

You have to post all 3 pieces of information to ProcessLogin.aspx, or else you get redirected to the normal login screen.  I was saying that you could automatically populate the username in your custom login dialog.

Same process as populating forms via URL? I've used things like this https://www.laserfiche.com/ecmblog/tech-tip-using-url-parameters-to-pre-fill-form-fields/

Just not able to get the webaccess link to function the same way.  Thanks for any advice Brian!

No, it's not like forms.  Have you read the documentation linked in the original question?  The point of this feature is that you can pass credentials to Web Access without using the Web Access login UI.  You have to cause that http post, which would often be via a custom page, and which can have whatever custom logic in it that you want.  That page could behave like forms if you want it to, but the important point is that the page does not exist - you need to create it.

Yes I've read it, I was looking to have the simply pop up with username populated with a passed token so i don't have to have users enter domain\username as we have windows authentication for the repo and forms you can enter the domain so users don't have to.  I've sorted out how to have the link go directly to the electronic document and authenticate with windows credentials.

It seems I was just trying to make it do something it wasn't intended for, at least not without modification I'm not capable of.  Thanks for your time!