How to use regex in grafana's object panel?

Hi,
My time series database object is
xxxx.xxx.21.xxx.xxx.xxx
xxxx.xxx.23.xxx.xxx.xxx
xxxx.xxx.43.xxx.xxx.xxx
In fact, I want to use regex to match the two number in the middle. This idea should be correct, right? Why can’t the grafana panel recognize the regular expression of numbers?

20210330172108

Or is there a better way to solve this matching problem?

Thanks

I forgot to say that regular expressions don’t work on objects in the visual graphics operation panel