Hi @dpenny2,
There are 2 ways to do that easily with WPCode.
The first one is the one you mentioned – adding the code to the Site Wide Header and using conditional logic to limit where the snippet is loaded.
The other option is CSS specific – because you are using a CSS snippet, in most cases you can target a specific page with the styles by including the page-specific class added to the body. Most themes will use the body_class function and that will have a class specific to a page or post by its id.
So you could wrap the style like this, replacing 2 with the id of your page.
.page-id-2 .your-header {
}