import logs for trend

[toujour]

Hi,
I'm looking for a solution about question below:

I have some LM5 in more sites, with their trends.
I want to see the trends in another LM5 (master) also with aritmetic functions (for example sum of the energy consumption by the all other site of the account).


Can I do it ?
Or Can I use a third part system for this scope ?

Thanks in advance,
Alberto