Few years back when i was working on SQL Server 2000, i had a client requirement to import EDI files into our database, i had then used ActiveX vbscript wihtin the DTS to parse and load the file.
Using SSIS, you now have 2 options:-
1) Use .NET script to parse and load the contents to a tables.
2) Use Script component within the Dataflow task to do parsing. Google on script component and you'll find plenty of resources.
Compare the performances of both the methods and choose the best one.
All the best