[R] Superscript text in axis labels

[Jim BRINDLE]

Hello,

I am guessing this is not a difficult question.  But at the same time, I 
haven't had much luck figuring this issue out from the R documentation and 
help pages.

How can I create superscript text in the labels of a plot?  The parameter 
along my y-axis is volume and my desire is for the y-axis label to read 
"Volume (cm^3)" except with the "3" in the superscript form/position.

Any insight or references would be greatly appreciated.

Thanks a million,
Jim