Set up sql server db mirror specifying IP address for mirroring_partner_instance

Ok. I run:

ALTER DATABASE DbName SET PARTNER = 'tcp://10.0.0.0:5022'

Command completed succesfully

Then run

SELECT DB_NAME(database_id) AS 'DatabaseName', mirroring_partner_instance
FROM sys.database_mirroring WHERE mirroring_guid IS NOT NULL;

mirroring_partner_instance comes back with a machine name.

I have machines on a different lan that won't recognise the machine name. I need it to come back with an IP address because this value is then cached at other .net applications for failover. (because of the brilliant geniuses who decide the "Failover Partner" value in a connection string should be completely disregarded)