I am sure someone will correct if I am wrong, but you can't claim VAT on foreign invoices unless you are registered for VAT in that particular country. It is generally not worth doing this but there are thresholds for each country and once these are reached then I believe registration is compulsory.
You would use the bank/credit card statements to work out the GBP paid, where possible. If paid cash, you can find the exchange rate for that day on xe.com.
You would post the expense so that it appears in box 7 but no VAT would be claimed. The items you mention are services, not goods imported, and that's why I understand they are not included in Box 9.