Reports Indirect Datakey/Keychain Expression

Is it possible to have indirect datakeys in a report?

For example: I have a dataset with datakeys of the form @Week X Day Y@ where X and Y are the week and day respectively. I have each week in a seperate page, so what I want to do is have a datakey of the form @Week (@Page@) Day Y@ where (@Page@) is the in-built page number and Y is the day. This way I could copy my tables from page 1 without having to update the week number on each new page.

Can this (or something similar) be done?