This is not an answer, but a place to aggregate information in the hopes of providing a solution in the future. Obviously Shashank's answer is ideal for anyone interested in just using R straight-up, and several questions on the right will help deal with going between the percent cells and regular cells.

According to the R Help archive, the types of R commands that give you this are

```
cars[,"speed"]
cars$speed
cars[["speed"]]
subset(cars, select = speed)
```

I'm not sure whether our interface supports the first three types of access to a data structure. At any rate I don't know where it would.

But more troubling is that I can't get the last one to work without something silly like

```
sage: r.new("subset(cars,select=speed)")
```

See this new Trac ticket for more details; I at least view this as a bug.

See also http://ask.sagemath.org/question/1420/r-through-sage-giving-errors-error-object-sage3