We need a script/procedure to be able to:
1. Import and link simple and configurable products in Magento. We only care for one attribute, product Size.
2. The script/procedure must provide the possibility to increase quantities, if product already exists on the system.
We have two CSV files to import, one for simple and one for configurable products. We can provide sample files if required.
Vers. Magento 220.127.116.11
P.S. Please advice if newer magento versions offer more features on this issue.