Your major misunderstanding must be that the comma separated values of an IN clause are usable as a table. No, it's merely a list of values.
So while syntax of [tt]field IN (val1,val2)[/tt] and [tt]field IN Select * from atable[/tt] are similar, this doesn't compare and IN (value list) can't use (value list) as a table to insert into another table.
If you have a file with CSV data the command to use to import it is BULK INSERT. For BULK INSERT you'll need one row per record, so a file with merely one list of numbers all comma separated and line breaks only due to word wrap will be read in as one record only, with 5000 columns, if that would be possible at all. You need another file format to import such data, turn every comma into a line break
Bye, Olaf.