Rules to Insert New Section

[rion]

I have posted this question before but does anybody have some samples that
would insert a new section to a repeating section in code? I have to insert
a new section in Repeating Section B every time a section in Repeating
Section A is inserted.

So if the user puts in the sections for Repeating Section A, there needs to
be 3 sections of Repeating Section B, as well as 4 fields matching data in
the corresponding sections.

Thanks in advance