[dba-VB] using a saved SSIS with VB.Net

I saved an import spec from the import wizard in SQL Server 2005.  I now
need to use that import spec in VB.Net, but I need to modify it.  I need to
change the source file, make it an append instead of a make table / append,
and I need to modify the datatype from NVarchar to varchar.  Of course I can
simply go back in to SQL Server and run the import wizard again, however
this is a fixed width file which means recreating all of the field name /
field width info a second time.
 
Is it possible to just do these mods on the existing import spec or should I
just bite the bullet and rebuild.  I have ~ sixty more files to import into
the table and I really don't want to do this 60 times.  The last time I did
this I actually built an Access app to create .csv files from the original
fixed width files.  It seems like the long way around the barn but then
again I do not see how this wizard is really very useful in this case.
 
Anyone?
 
John W. Colby
Colby Consulting
www.ColbyConsulting.com