Are you using an old way to do this? One possible way to do this is to store the portal row number in a global variable so when you return to the layout with the portal use the script that returns you to the layout to go to the portal row saved in the variable. You could also use a script trigger.
Thanks for the reply rgordon.
I do use the global variable and script triggers already, but in one instance (the most common) I'm simply closing a print preview window and the existing window remains open and unchanged.
I was hoping that portals had gotten smarter, but I may end up doing as you suggest and just use a script to close the preview window and return to the original window.