case unsensitivity & incremental search in Interbase

I wrote a very simple code to make an incremental search in
Interbase with a help of "MyTable.FindNearest" function.
Unfortunatly (for me)  it is case sensitive.
Delphi 2 has function "locate" with case unsensitive option,
but it doesn't set the cursor on the nearest record when
search failed, so it doesn't suit the incremental search.
Are there some ways to do it without TQuery component with
SQL command SELECT ..UPPER(Field) etc ?

Joel Golovaty