Hi David,
If you're importing a fixed width file the answer is no, because there's
no set relationship between the field type in the database and the
number of characters in the text file.
If it's a "delimited" text file, it's possible in principle but you may
not need an import spec at all: Access attempts to convert the values in
the text file to the field types of the table you're importing to. You'd
iterate through the Fields in the table's TableDef to work out their
properties, and either build an import spec in the undocumented system
tables or (and simpler) create a SCHEMA.INI file containing the spec.