When you set up the database, define the region column like this (for example):

Column Name:
REGION

Column Type:
ENUM

Column Values:
N
E
S
W
NE
NW
SE
SW

Form Names:
same as in Column Values

Form Values:
North
East
South
West
North East
North West
South East
South West


Assuming you don't use the default template, you could put this in your custom search_form.html:

<select name="REGION">
<option value="N">North</option>
<option value="S">South</option>
...
...
</select>
<input type="hidden" name="REGION-opt" value="=">


Or via direct URL (example for North East):
yourdomain.com/path/to/db.cgi?do=search_results&REGION=NE&REGION-opt==

Let me know if this helps.
liver