Making a visualisation from multiple searches

Hi,
I played with kibana for the past 5 days but I'm unable to find how to do what I want, I'm starting to think that it's not possible

I have a huge log file that look like data

A logstash forwarder is sending it to logstash and logstash is feeding it to elastic search.
My logstash is configured this way :

I'm interested in 3 lines of log
1 : msg = Sending to ELK
2 : msg = ELK failure - rejected
3 : msg = ELK failure due to us

I find them by searching for msg:"Sending to ELK" for example

So what I want to do is display a line graph with log_date on the x axis and this on the y axis :
(CountMsg1-(CountMsg2+CountMsg3))/(CountMsg1/100)

However in visualise it looks like I can only do one search, not multiple ones and not math operation.

Did I miss something?

Thanks

Nope, you can't do it this way yet.
You may be able to with a scripted field though.