Richard,
There is nothing special. You just type substring as it is, with spaces or whatever. Without quotes.
Please make sure that in the Find dialog the "Match whole string" checkbox is not set.
If it is not, send me a private message with screenshots of:
- The Find dialog just before you start searching for any of your variants with no results.
- The Find Results window for Corel. On the later screenshot, highlight items that you expect to match your variant.
Regards
Sergey