You can create a BANK account e.g nomnal code 1260 in the BANK section and use it to create your expense account.
So when you pay for an item you select the bank Account 1260 you had created, and record the items you have purchased as a payment.
If you need to be reimbursed for your expenses you then use the Bank Transfer option to transfer lets say £50 from your Current bank account to the expense account