Paul:
The symbol you want can be accessed one of two ways:
1) From the Insert menu, select Symbol. You'll see a dialog box. From the
drop-down menu, select Latin-1. The symbol is in the 7th row, 16th column
from the left (about half-way);
2) Press Cntrl + /o (Press and hold the Control key plus the "/" key then
type the lower case letter "o".)