Campaign Id related tables or Function Modules

Hello,

I have some doubts related to Campaign. My requirement is to get the Campaign Id from

E-selling to CRM using Badi and do some validations for an Order/ Quotation.

First check if this Campaign id exists and is valid for the current date.

How to check if this Campaign Id exists? Is there any table in which all the Campaign id get stored?

Second Check is to check if the Sold-to-party belongs to the target group link to the campaign.

How to get the Target group details for a campaign any table or Function Module available?

Third Check is to check if the entered product belongs to the campaign (managed at item or COS level (product hierarchy)). How to find this?

Any help will be highly appreciated.

Thanks & Regards,

Jayanthi