How do I post disallowable expenses in VT?

Historically, I have entered all expenditure into VTT+ and then manually added back depreciation and private use adjustments in the tax computation.  However I am now trialling BTC software and attempting to import sole trader accounts into SA section of Self Assessment Tax return.  I therefore need to enter disallowable expenses into VT so that I am importing the allowable expenses only.  I am not sure what entries I need to make in VT to achieve this as I have never used the disallowable expenses ledger before.  Can anyone help please?