How to get a Custom SF Button/Link Open a Popup window instead of a new browser tab?

We have button that references a Custom SF Button that opens a Conga Composer page. In standard Salesforce, this button opens a pop-up window. In Skuid, it opens a new tab. How can we make it open a popup instead?

So, I just recreated the button in Skuid, made it a popup, used a template field to host an iframe with the content of the conga button, tweaked to match skuid-compliant variables working good. 

Super!  I love a good hack when I hear one… 

Hi Jack,

With the pop up are you able to stay on the same page?