Рискну предложить использовать функцию SETRECORD:
Цитата:
SETRECORD (Form)
Use this function to select the current record shown on the form.
Form.SETRECORD(Record)
Form
Data type: form
Record
Data type: record
The record you want to select as the current record.
Comments
You can use this function to select a record to display when the user opens the form. If you use this function for this purpose, it will override the SourceTableRecord property "Saved" setting: the current record will not be saved in the setup file.
К примеру, вот так:
CurrForm.<Имя субформы>.FORM.SETRECORD(<Record>);
Или я не правильно понял вопрос?