Thank you Jason - your suggestions and sample code are most appreciated.
Unfortunately, I am not familiar with writing VBScripts and have no
tools to write it.
My preference is to keep the whole development code in Delphi and
avoid using additional external applications, such as OLEDB provider.

The data parsing method described in the Delphi-InterBase.PDF manual
("Inserting Data from an External File") works perfectly well, as long
as all data rows have identical lengths.
I am now considering writing a code to eliminate the initial irregular
title rows from the external text file (using simple ReadLn / WriteLn
Delphi functions) and then use the built-in Interbase method to
directly parse the remaining regular data rows into the temporary
Interbase table, as per Delphi-InterBase.PDF manual example.

Would you have any other, better suggestions ?

Kind regards,
Mario