Group Lines Excel Function

Hi,

I have an ALV Tree (cl_salv_tree) that's works fine.

But I need to export all data to excel.

I am using OLE objects to do this.

I would like to know if is possible group lines into excel.

For example.

Today works like this

Level1 -

Value 1

---Level2 --- Value 2

---Level2 --- Value 2

-

Level3 - Value 3

I would like to do this (compress the Leve2, for example)

+ Level1 -

Value 1

-

Level2 -

Value 2

+---Level2 -

Value 2

Thanks a lot.