Combine several lines of text into one cell

hi everyone

I hope you are all well! I have an excel problem and it would be much appreciated if someone has the time to take a look...

In column A I have product names, in B I have product categories and in C:H the product categories from column B are titles and the name of the subcategory is written in the cell.

Because there are mutlipule sub categories that a product can belong to the report produces mirrored lines with one sub category on each line.

What I need to do is combine all of these subcategory entries into one cell separated by a comer (,)

Any help you could give on this would be great, thank you v.much for your time!

Pete

P.S if you have a way to get rid of the copied lines after that it would make life a lot easier tooo. Thanks.