[GNC] Advanced Portfolio Report - Fund managment fees

[hal.lol at tutanota.com]

Hello,
I have a mutual fund account for which the management fees are paid for in shares. That is to say, every years, some of my shares are used to pay for the fees and my total amount of shares is therefore slightly reduced.
I am trying to setup my accounts/transactions in such a way that early management fees for the mutual fund will appear in the report as brokerage fees, but so far I haven't been able to figure out the trick to do so. First, is this even possible?
If I simply express this by a normal 'sell' operation, where the money goes to an expense account, the report shows some 'realized gain' and no increase for the 'brokerage fees'. I would like the opposite: the money out should be added to the 'brokerage fees' (it goes to an expense account after all), and I shouldn't see any 'realized gain'. The total return and return rate should of course also be updated accordingly.
I am using Gnucash 2.6.16
Thanks!