I have a large dog exercise pen like the one pictured below that I will eventually use as a mobile run Note: I will cover it for predictor safety and sun protection. This is for modified free-ranging once they learn that "coop" is home base! Question: How do I get the chickens to leave the coop (I have the Raised Durango with attached run) and move in an orderly fashion into the pen area ? Something tells me I'll have to move them one at a time by picking them up. Ideas ? I presume that by allowing them to forage close to dusk, they will go back to their coop on their own afterwards.

I think you have the right idea. You'll have to start by picking them up and moving them out., but over time their curiosity should get the best of them after they start to feel "safe at home" so when you put the run out for them they'll move in slowly to see what's there to forage on and explore.
I have a similar "pen" arrangement for when they're out of the coop. What I tried to do was condition them to think there are treats in that pen and I reinforce it by throwing in mealworms or other treats when they first get out and they run right into the pen. Now, that is our ritual and I've done it enough that they will head straight there sometimes without treats even (unless there is a distraction like a cricket hopping the wrong way!). Didn't take long but I noticed that they will automatically head back to the coop when it got darker ...
I have the same problem, but in reverse! My hens are very happy to race out into the garden, but I have to bribe them back into the coop with chicken crack (scratch feed—which I don't give them any other time.) This is only if I need them in before the sun goes down; otherwise, they go in on their own.
Out of necessity (we expanded the coop this week), the girls needed to go to "temporary housing". I set up the x-pen and herded them in - aka bribing them with a "shake of the red cup" that has their sunflower/mealworm treats. They enjoyed being on the side of the yard with some sun. And now, I'm hoping to give them time in their "sunroom" a few times a week. I bribed them again later in the day to go back to their coop.
P.S. Mabel, the Australorp laid a brown egg right in front of the feeder - can you see it?
Here's a picture of the new coop (We added a 6x3 run in the front of the original Durango raised coop.) - It's amazing! Technically, they could stay in their all the time but I like for them to get some Vitamin D in the winter.
.