Automated user creation

Hi,

recently I have started a project written in php, which needs a subdomain. The situation is like that:

1. User goes to example.lan/register
2. subdomain must be created like "xsf.example.lan", which is owned by another user (xsf for security reasons)

How can I automate this process? I have found some documents with ssh howto create domains and subdomains and I can do this without issue with ssh, but is there an easy way to do this via php api ?

Thanks, Dean