Uploading journals using the Audit Trail Transaction template to Sage 50cloud and looking to understand the Exchange Rate column.

Just want to check whether this understanding is correct as the comments on the Template aren't very explanatory and I can't find anything on the help files (although  I might be looking in the wrong place).  i'm always accustomed to journals taking up two or more lines, with separate lines for each nominal account reference, so I am puzzled about the instructions which require both an Account Reference and a Nominal Account Reference on each line.  The description "The nominal code originally associated with this transaction" for the Nominal A/c ref column is also puzzling me since, before the entry for the transaction is uploaded there is nothing originally associated with the transaction as it doesn't exist!  There is also no clue as to which way the currency transaction goes: is it NetAmount*ExchangeRate or NetAnount/ExchangeRate.

My guess is this (am I right? and if not, how are they done)?

Let us say I have a bank payment of 10,000 GBP from a GBP bank account (say a/c 1200) which is a transfer to a USD bank account (a/c 1210) and the exchange rate is 1 GBP = 1.25 USD
would the (partial) entry be:
Type BP
Account Reference 1210
Nominal A/C Reference 1200
Net 10000,00
Exchange Rate 1.25

(and would the corresponding entry in a/c 1210 automatically show the type as BR)

If I then paid a bill of of 5,000 USD to a supplier whose account was set up in USD,  would I record
Type BP
Account Reference SUPP001
Nominal A/C Reference 1210
Net 5000,00
Exchange Rate 1

Finally, if I paid from the same account a bill of 3,000 USD to a supplier whose account was set up in GBP, would I record
Type BP
Account Reference SUPP002
Nominal A/C Reference 1210
Net 3000,00
Exchange Rate 0.80     (i.e the inverse rate USD-> GBP)

Any help (or a pointer to a set of instructions which explains the template) gratefully received.

Malcolm