Samba4 how to extend the schema

[steve]

I have an ldif with entries like this:

dn: CN=automountMapName,CN=Schema,CN=Configuration,DC=YOURDOMAIN
objectClass: top
objectClass: attributeSchema
attributeID: 1.3.6.1.1.1.1.31
cn: automountMapName
name: automountMapName
lDAPDisplayName: automountMapName
description: automount Map Name
attributeSyntax: 2.5.5.5
oMSyntax: 22
isSingleValued: TRUE

which I'd like to add to the s4 schema.

Can anyone point me in the right direction?
Cheers,
Steve