Configure the Data Transform as follows to copy the details to an embedded page on the subcase. The Parent case will have pagelist (1) through pagelist (x). The subcases will be populated with pagelist (1) containing the contextual data used to create the subcase. The Pagelist property must be visible to both the parent and subcase.
Data Transform (DT) Uses a tmpPage Parameter to hold the contextual page as the source for the values. Declare tmpPage on the Pages and Classes tab of the DT specifying the Class of the PageList. On the Parameters tab, specify tmpPage as an IP parameter with Data Type Page Name.
The Data Transform Reads as follows:
Append and Map to .pagelist a New Page
Set .Prop1 = tmpPage.Prop1 (Add more lines for other properties to copy)
On the Create cases smart shape:
Create Multiple Cases
Source Page Parameter name = tmpPage
Data Transform = DT (or whatever it is named)
If you only wanted the index you could use the same idea above using the Data Transform to copy current the index to the target page.