Melanie,
As many of us have, you're learning these system as you go. AC doesn't have a big manual but with these boards and some playing with the program, you can really figure out all the ways to use the program.
With my practice version of v5 that I'm using, I configured the system like you have it set-up. 2 docs, then a provider that is labeled "Walkin Clinic". I placed patients in each clinic. I was easily able to grab a patient from the walkin clinic and drag-and-drop into a docs clinic. The windows never closed. Not sure what's happening with yours. Just make sure you have All Providers clicked at the top.
I think this is a perfect set-up for a multi-doc walk-in clinic. We have all asked for some updates to the scheduler such as color coding of the patients when they arrive, when they are roomed, and when they're gone. Most would also like a quick little check box (or something) next to their name so when they check-in, the box is clicked and documents a time of check-in. We also would like to have 30 minute appointments without the patient's name showing up 2-3 times (depending on the length of your standard appointments).
So the scheduler is not perfect. But for what you need, it should work very well with a manual documentation of check-in time in the comments section as you have suggested with a reason why they are there. i.e. 9:32 Rash
