Use script-step Go To Related Records [ your child table ] and base it only 'match current record only'
This provides a list of your detail records (you haven't described what they mean). Export these child records instead ... and when you do so, include fields from the parent table as needed.
If you are export to Excel, for instance, you will have same parent and one detail child record per line (which is considered a record) because it is a flat file. There are ways you script such a process where the children are grouped via variable or calculation but we would need more information to advise properly. Specifically, what does the result export look like? What will you be doing with the information? What is the program which will inherit the resultant data?
And to export only the current record, make your current record the only record in your found set.
The GTRR script step isolates to only the related records for the current record. The request by MSpsi was to export the child records; the parent record will be exported line for line with each child.
Bah my long response just disappeared!!! Can I send a PDF of my TOG Table?