How to change the "add to cart" to an hyperlink?

Hello.

My website promotes rare goods that I don’t own.

I mean, I own and resell only the 20% of the goods I am advertising.

I made my website homepage using only 1 collection from Shopify, so I need to change the add to cart button to an hyperlink that redirect my customers to other sellers websites and, let say every 4 or 5 items I will post an item that I own and only at that point I will need the add to cart button.

Is it possible or I am completely wrong?

Yes, It is possible to do it. It would require custom coding and probably hire Shopify developer. Contact me if you need my help.

Thanks.