Note: This was originally posted by an inactive account. Content was preserved by moving under an admin account.
Drew, it should just be pass-through R code, so you would use something like the following:
NOTE: in the following example "in1" represents the name of the input pin for the node and "out1" represents the name of the output pin for the node. These names can be seen in the "define" tab near the bottom.
myRData = in1
# do something with the data
#...
out1 = data.frame(myRData)
Let me know if this doesn't answer the question.