When you enter the bank (or cash?) receipt (T9) post it to either a loan account in the TB section of the nominal (2300?), or to the directors current account.
If the loan is expected to stay in the business for a while, if it is a significant sum or if the company will be paying interest to the director I would post it to a loan account. If it is just expected to be a short term small loan I would just post it to the directors current account.
If using a loan account, I would re-name the account to include the directors name.
That's how I would prefer it to be entered if a bookkeeper gave me a Sage backup to prepare accounts.