How to customize alert in sap PI 7.0

Iam able to generate alerts using standard Alert configuration.

In our environment , we have different namespaces for different scenarios.

Now based on the error message, we need to categorize the mail to specific receipients.

As I browsed through forums, I have got SALERT_CREATE rfc.

But I didnot understand How to use that.

Could any one helpout of it.