@jen It would be something like this...

SELECT
	Payment.TranDate,
	Payment.TranID,
	BUILTIN.DF( Payment.Entity ) AS Customer,
	Invoice.TranID AS InvoiceID,
	TransactionLine.ForeignAmount
FROM
	TransactionLine
	INNER JOIN Transaction AS Payment ON
		( Payment.ID = TransactionLine.CreatedFrom )
	INNER JOIN Transaction AS Invoice ON
		( Invoice.ID = TransactionLine.CreatedFrom )
WHERE
	TransactionLine.Transaction = 1450781

That's pretty messy, but it might help.