How to group values - data preparation

Hi,

I have an Excel file which has subtotals and categories as included in the file. I would like to use the Group Selected Values option and use calculations to have the subtotals. But I could not get through the grouping first.

Showcasing:

Order                                   Act

-------                                   ----

1 Book                                   5 €

2 Notebook                         3 €

3 Pen                                   1 €

* School Expenditure          9 €

Here I would like group these 3 rows as school expense and calculate the subtotals via Lumira.

Any ideas on this?