Situation:

- We identify Accounts by Country and VAT number.

- We want to import various external lists of Leads containing these values. 

- The intention is to PREVENT the data duplication, i.e. convert only the relevant leads into Accounts and Contacts. 

- We export the Account & Contact data from CRM into Excel, do the mapping via Excel LOOKUP function, filter the records not found in CRM in the external list of Leads and import only these leads into CRM now.

Is there any possibility to define the following formulas for Leads:

- "Account with this Country and VAT Number exists Y/N"

- "Contact with this Country, VAT Number, Last Name, First Name exists Y/N"

to easily find relevant leads for the conversion? If not, is there any better workaround for that? 

Thanks

Roman