Implement validation based on numeric value

This feature request is based on following:

I need to implement a validation, based on value of ContentLength. The test should fail if ContentLength equals 0.

I have read the info about validation here. But this only works for validation on strings.

I want to have a validation based on numeric value of a response. Of course, the value of the Contenlength changes for every request (it's not a fixed value). Only thing that counts is that validation should pass if ContentLength value > 0, and that it should fail in all other cases.

There is currently no easy way to implement such validation. I would like LoadComplete to be improved with such easy validation. See attached screenshot for clarification.