Improving Company Identification: Using LinkedIn URLs and Domains

I do have a question around "excluding companies" when using "Find companies". I experienced that using the "domain" to exclude is failing to often. I therefor think the "linkedin company url" would be more reliable. As I do not always have the "linkedin company url". Can I create a column which contains both "Linkedin Company URL" but also "Domains" and use this as the "Company identifier" column?