You could try using a filter ont the table you are searching e.g.

* work out how long the search string is
nSearchStringLength = len(thisform.txtSearchString)
* select the searched table and set a filter on the field you want
SELECT mytable
set filter to left(MyTable.SearchedField,nSearchStringLength)==thisform.txtSearchString
Browse for fields ....

If you want to use the find dialog, on your browse, you will need to have the menu item available on the edit menu. Additionally you could use an on key label to move the record pointer to the nearest letter match but these two approaches seem to be mutually exclusive of each other as you have no way of switching off the on key label if someone trys to use the find from the menu.

Penda