title: How to literally print superscripts in R not used in labels or legends?
body: <p>I know that in a graph one can use expression() to include superscripts, e.g.</p>
  
  <pre><code>plot(rnorm(20), xlab = expression(paste("n"^"th")))
  </code></pre>
  
  <p>However, I literally want to print out superscripts, so I can store them in rtf files later. In fact, I want to use them to indicate the degree of statistical significance associated with my regression coefficients (you know, like "0.24^*").</p>
  
  <p>With "<code>expression(paste("n"^"th"))</code>", I tried <code>print()</code>, <code>cat()</code>, <code>eval()</code>, and <code>get()</code> but none of them worked. </p>
  
  <p>I am currently using the "rtf" package to output ".doc" files. If someone suggests using other ways/packages, it is OK if R itself cannot display rich formats in the console, but the results can be stored in some files anyway.  </p>