you will not be able to directly -- but, we can easily write a control file that can load this sort of data. What you would need to do is write a control file based on the header record -- then it is easy.

control file:

LOAD DATA
infile data.dat
replace
INTO TABLE T FIELDS TERMINATED BY ";" ( a constant 'F100', b )
INTO TABLE T FIELDS TERMINATED BY ";" ( a constant 'F101', b )
INTO TABLE T FIELDS TERMINATED BY ";" ( a constant 'F102', b )
INTO TABLE T FIELDS TERMINATED BY ";" ( a constant 'F103', b )
INTO TABLE T FIELDS TERMINATED BY ";" ( a constant 'F103b', b )


command line:

$ sqlldr / t skip=1

SQL*Loader: Release 9.2.0.4.0 - Production on Mon Feb 16 14:53:37 2004

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Commit point reached - logical record count 2


and resulting data:

ops$tkyte@ORA920PC> select * from t;

A B
---------- ----------
F100 GB09
F100 GB09
F101 0000712061
F101 11003930
F102 0
F102 0
F103 2
F103 3
F103b NULL
F103b NULL

10 rows selected.



At worst -- you'd have to write a script that got the first line of the .dat file, to generate the ctl file you need to load with.