embedded html in a table row

i have a table with a weather forecast.  each row says something like 
"50@ - 70@".  [the @ represents the html "degrees" symbol.]  sometimes, 
however, (in the evening) the first row says just "low of 50@".

what's the best way to accomplish this?  i discovered the hard way that 
i can't span the whole thing and substitute, because the degree signs 
wind up as "°" on the page.

should i put span tags around "50", "70" and also around "- 70@" so i 
can remove the child from the row?  how do i put the child back so i can 
clone the rest of the rows?

should i put a span around the whole thing, clear the span's text, and 
add a cdata section with "50° - 70°"?  ick.

thanks for your thoughts,

  -- mike