You can accomplish this using the RegexReplace formula. This takes a value (your company name), a regular expression and a replacement string. Try [Company Name].RegexReplace("^The ", ""). This will match any value starting with "The " (case sensitive) and replace it with a blank value. If you want to match the or The as a prefix you’ll need to use [Company Name].RegexReplace("^[Tt]he ", "")
Another way to accomplish this is by matching using startsWith and then dropping the first four characters: If([Company Name].Upper().StartsWith("THE "), [Company Name].Slice(4), [Company Name])