Depending on who the NS server is for your domain..
The Name Server (NS) should hold the extra records..
do dig -t ns your.domain
then organise with that server to enter the extra records.
If you have a dynamic number, you won't be able to host services unless you use a redirecting service such as www.dyndns.com
Do a Google search for "dynamic dns register" and find one that's close to you..