Hi Alex,
According to my understanding you need to insert two blank lines before the group right?
For that you don't need to insert blank values in the database end. In the Crystal designer you need to follow the below steps.
1) Create a formula as group name "Blank gp" with below content...
WhileReadingRecords;
"";
2) Place the formula in any place of the report.
3) Select "Report" Menu --> Select "Group Expert" --> select the "Blank gp" for two times, after select the required filed for grouping.
Now your report will display as per your requirement. Hope the above information will help you.
--Naga.