Monthly Summary Reports by eMail

Hi,
I would like to add following feature and need someone, who can help me in implementing it:

Monthly Summary Reports by eMail

WHAT
HikaMarket with pre defined Buyer Groups

+ Buyers need to register on the platform. This is done by the HikaMarket administrator in the backend.
+ All buyers have the same delivery address.

+ One of the buyers is the administrator of the particular buyer group.
+ The groups administrator gets once a month a file per eMail with a summary report of all purchases last month.
+ The summary report includes information like who did order when what, how much did it cost per user last month in total
+ The format of the file will be either Excel, CSV, or similar (needs to be defined later on)

Probably a CronJob should make it - if you have relevant experiences I would be happy to talk with you, ideally by PM.

Thanks.