Prices in CSV

-- url of the page with the problem -- : metalearth.shop
-- HikaShop version -- : 6.1.1
-- Joomla version -- : 5.4.0
-- PHP version -- : 8.2
-- Browser(s) name and version -- : firefox

Hello,

I want to change prices of products in my shop.

So, I export to .CSV file, opened in EXCEL.
Then prices are given in format "Standard" and e.g. like 14.99 (numbers with a DOT).
When I change the price in this CSV-file the format is changed, e.g. "14.99" I want to change in "9.99" but what appears is "346094" ????

How can I solve this problem ?

Thanks for help-

Rolf