Need your Inputs - where do i store data of around 4000 Characters which is related to an Employee's

Summary

Need your Inputs - where do i store data of around 4000 Characters which is related to an Employee's User account

Content

We have a need where we need to store data related Employee's AD Account with some alias email address. All these email addresses are concatenated and needs to be stored somewhere in Person or Assignment attributes. i did check all those tables and no field has that length.

Could you please suggest me where do i store this information?

Thanks

Mansur