Distinctive Ringtones for Internal Calls

[harrys]

We have 3 reception phones all on mute (They sit together at the front) and one ringer phone. All 4 phones ring with an internal call,
The ringer phone is set to distinctive ring for internal calls but if there are already calls in que from external numbers then the disctinct ring doesnt work when an internal call comes through until all the external calls are sorted.
Is there a way to priortise the ring tone to switch to the internal call even if it is at the bottom of the call que?