Validation rules for Country codes(USA, Mexico, Argentina, Canada, Australia) in Salesforce

Example:

OR(
AND(
ISPICKVAL( Country_Code__c , "USA"),NOT( REGEX( Pincode__c , "\\d{5}(-\\d{4})?") )
),
AND(
ISPICKVAL( Country_Code__c , "MEX"), NOT(REGEX( Pincode__c , "\\d{5}")), NOT(REGEX( Pincode__c , "\\d{6}"))
),
AND(
ISPICKVAL( Country_Code__c , "AUS"), NOT(REGEX( Pincode__c , "\\d{4}"))
),
AND(
ISPICKVAL( Country_Code__c , "CAN"), NOT(REGEX( Pincode__c , "[a-zA-Z]{1}[0-9]{1}[a-zA-Z]{1}\\s[0-9]{1}[a-zA-Z]{1}[0-9]{1}"))
),
AND(
ISPICKVAL( Country_Code__c , "ARG"), NOT(REGEX( Pincode__c , "[a-zA-Z]{1}\\d{4}[a-zA-Z]{3}")),NOT(REGEX( Pincode__c , "\\d{4}"))
)
)