[R] Identifying a subset of observations on a 3d-scatter plot using cloud()

[Giam Xingli]

Hello everyone,
 
This is my first post to the mailing list, so I hope I am posting my message the correct way.
 
I am trying to present my dataset in a 3d scatterplot using cloud() in the {lattice} package. I hope to explicitly identify a subset of my observations. The observations in this subset need to satisfy the following critera (values on x,y, and z axes above a certain cutoff value). It will be great if I can get advice on how to annotate the points representing the subset of observations with a different colour, and if possible, label the points.
 
Thank you in advance for everyone's help!
 
Best regards,
Xingli Giam
Department of Biological Sciences,
National University of Singapore