Client tag in alarming display path

Hello. I am trying to add client tag value to some tag alarming (into Display Path). I understood alarming not work with client tag. I tried to use runscript in expression of Display Path, but this did not work.

i need get construction like this in Display Path
{[System]Client/User/Username} + […] {Desc} +’ | Change value to '+ {[…] Value}.

Display path is computed in the tag in the gateway, where there is no client context at all.