Variable treshhold based on data points

Hi all,

I'm trying to figure out how to make this but I cant seem to get this working.

I've created a datasource which runs a script on one of my remote servers, this script will return with 2 value's for example: Data |connections=160 maxconnections=2000.

Next i've created 2 datapoints named connections and maxconnections.

Now I would like to create a treshhold for when the connections have reached 90% of the maxconnections, is there anybody that can help me with this?

I've looked at the UsedBlocks treshhold, I understand the meaning of it but how should I add that in the treshhold based on the above datasource and datapoints.

Thanks in advance.