I'd be tempted to just use Monarch to break up the large document into smaller documents.
Quickly build a single line detail template without traps and paint a single field named ReportLine which goes from one side of the report to the other so as to capture every column.
Build two runtime parameter calculated fields, FromPage and ToPage, and hide them from view in the Table.
Build a Page Number filter with:
Page() >= FromPage .And. Page() <= ToPage /CODEand export from the Table window to a text file using the Page Number filter.
Who says that Page() has no practical value in a filter expression?
Edit: Be sure to go into the Options and turn off the choice to export field names.