CDN! This should be easy: Adding simple external image - replacing field_image

Hi,

I use Drupal 7 and use a theme called St. Quatro - now I have a CDN and instead of uploading images I want to enter an external URL

So, I went into the structure / content type / and tried editing the image module with no luck. I installed various modules like "Media" and "Remote Wrapper" with no luck.

Is it really that difficult to replace field_image and instead have a text field that allows me to enter an image URL and then render it?

Appreciate your help, I'm still new. Please consider adding this to the default Drupal - a lot of people use external image sources and do not upload files

Thank you
Oliver