Regular Rollup Option for Runtime

[Sumeru]

Hello Folks,  my Cube model has its datasource as FM package which is an Audit package in which i'm pulling in "RunTime" query item to report the number of times, reports ran for more than 2mins over a given period of time.My question is what option should i use to set its regular rollup property,since i dont want any operation to be performed on it by cube. is there a way that i can still get runtimes of reports just like tht.