Nope...you can open an image from LR into Photoshop as a Smart Object and retain raw editing. But LR is a stand alone app.
To better answer your question, it might help to know more details about what you're up to.
Rob, I like a few of my presets that I have created in LR but want to quickly mask off a few things from the image. In cc I have the ability to copy a layer then run a filter on it with ACR then I can mask off where I don't want the affects. I was hoping to be able to do the same with LR since I primarily use LR. I love LR for the simplicity and quickness of it, but don't always want everything applied globally, and many things are still missing from the brush options in my humble opinion.
I guess Jeff Schewe's answer was the best you can get - no way to do that with Lr.
Lr has an SDK which can be used for full automation, but you can't "mask a preset", only those things you're familiar with can be masked (e.g. brushed..).
No layers in Lr..