OIM custom table to store idenity multiple values

Hi,

I need to implement a customization in OIM where an

identity may belong  to different

institutions and have different roles in each institution. We also need to send

this data to some applications.

How can we achieve this? Custom attributes with

multiple values are possible? Create a custom page with a custom table to

manage this data is a good approach? How can we then update these attributes using

OIM API? This data comes from a trusted source, is then possible to update this

custom table?

Thanks in advance.