Cross Validation Rule to prevent other companies from using the accounts

Summary:

clarification on Cross Validation Rule

Content (required):

i have a company (320), and i have 4 accounts. i want this company to be the only company who can use those accounts. but i also want this company to use other accounts. the important issue here is to prevent companies like 101, 200, 350 etc' to use those accounts. what CVR is required for this? what do i put in Condition Filter and what do i put in validation filter?

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):