Custom fields customization

Hello everyone.

I’m trying to find files of custom fields on my wordpress ftp, because i need to change structure.

I want to display icons on my contact box. So i created an html structure that i can put directly on custom fields on my wp-admin. But i don’t want to write same code for all my post. So i need to found file when custom fields draw structure with html labels, i hope there is a php file with html too, like template files.

Anyone knows about it?

Thank you.