An internal EB link just appends ?page=<your-page-name> to the URL. You can try using that with @JeffreyThompson2 's approach, and I think it would work all right.
Another option is to just put that link into a button or something in your EB app. Does the link change per feature? Or is it always linking to the same page? If it's not coming from the specific feature, I don't really see why the link needs to be in the popup at all.
- Josh Carlson
Kendall County GIS