Dynamo with Revit 2013 - Select grid lines and levels

I'm new here so I hope I'm at the right place.

I want to know if there's a way to select multiple grid lines and levels in an existing project with Dynamo for Revit. We can select a level, but I didn't find a way to select more than one at a time. Also, I didn't find anyway way to work with existing grid lines.

Thanks a lot!

I need to select grids and use them as a reference to create lines, walls, etc.

Where I work, we receive projects with existing grids and it would be useful to be able to use them instead of recreating our own reference.

Hope it helps, and my apologies for my English.

We are working on some generic selection tools: Vertex, Curve, Face, Element, Family and similar tools for parameter extraction. Not sure when they will be out, but definitely on the radar. Can you tell us a little about the kinds of things you want to be doing with these tools?