Possible to do a simple "A" record update using a URL via the API?

Hello,

I need to update a single "A" record in the DNS for a domain. The 'trick' is that I can only use a single URL. Is this possible?

For example, something simple like this:

/api/?pw=pass&un=user&hostname=my.domain.com&ip=newip

Unfortunately, I'm not able to do the update with a script or anything like that... I can only specify a single URL.

Thanks!