Can I import external Potentials and/or Contacts and have them be linked to Accounts? Can I link existing Potentials & Contacts to existing Accounts?

Can I import external Potentials and/or Contacts and have them be linked to Accounts? Can I link existing Potentials & Contacts to existing Accounts?

I have a list of existing external Potentials that are associated with existing external Accounts.  I want to import both (from Excel spreadsheets) into my Zoho B2C CRM and have the Potentials and Accounts that are the same name (or policy #, or some other field) be associated with each other.  Can I do something to the data to get them to match automatically after they are uploaded?  Do they match by name or could I use some other field for matching?  Or, can you manually or automatically match up Potentials and Contacts with existing Accounts after they are uploaded?  Or, is having a Potential or Contact associated with an existing Account really only happen as you create them individually? 

Thanks for you help, if I can figure out how to make this work and it will really be fantastic.