Yes, using the Insert command. You'd add a rule on the Qty field, and set the command field in the QdabraRules secondary data source to something like:
Insert /parent=/my:myFields/my:Insert /child=/my:InsertGroup /count=1
The XPaths in the arguments will need to change to reflect your data structures. So, for example if your repeating group is called group2 and is in another group called group1:
Insert /parent=/my:myFields/my:group1 /child=/my:group2 /count=1
Count is optional and defaults to one, so you wouldn't have to include it in this scenario.