Exclude specific product from promotion calculation


I’ve been looking for hours now on already, but i cant find a possible solution anywhere, i’m kinda lost and would really like some help on the following:

I have free shipping promotion set up for orders >= 100 euro. Thats works just fine.

Now i’ve added some ‘Gift Cards’ which customers can buy in the shop, those can be 10, 20 or 50 euro, and all have the product shipping option set to ‘free shipping’.

The actual problem arrises when someone adds a gift card for 50 euro (which as a product has free shipping anyways) and any other product from the shop for 50. The promotion will (logically) say: Hey order total is 100 euro, so here’s your free shipping!

So i would like to exclude either the products or the category from the ‘Order Subtotal’ condition calculation when checking out the promotion.

can anyone advise?

i’m using cs-cart version 2.1.4 professional