In order to access raw Sage data via a supported interface use the Sage reports process.
The most common way of doing this is to

1. Open the Nominal ledger
2. Click on Reports
   
3. Select the Nominal Departmental Analysis (Detailed) and click Run
4. A Criteria dialog box appears, leave the Nominal Code field empty and set the date fields to the appropriate values
   
5. When the Report is displayed, click on save as and save the file as a CSV file.