I'm desperate

A self-join relationship should do what you need. In the file with the hours, define a relationship to the same file using a match field that will be the same for all entries for a given agent and project (the contactenated ID_Agent & " "& ID_Project).

In the calculation, use Sum(SelfJoinRelationship::HoursPerAgent) to get the figure.

I'm not sure what you want in the second part, I think the self-join relationship (and perhaps other self-joins) can get the dta you need.

Does this help?

Thanks for your answer, CyborgSam, but finally I made using the GetSummary function. That was the cue. Of course It can be done also by a Self-join relationship