Attaching Custom 128 bit Characteristic UUIDS to Custom 128 bit Service UUID where the base does not match


I am trying to emulate a vendor's tool, whose BLE properties are configured as follows:

Custom 128 bit Service UUID like XXXXXXXX-0000-XXXX-XXXX-XXXXXXXXXXXX

Custom 128 bit Characteristic UUID like XXXXXXXX-0001-XXXX-XXXX-XXXXXXXXXXXX

There are five more characteristics like this. 

With the nrf5 SDK, it appears that I can add a characteristic to a service with a base UUID, but it will modify the 12th and 13th octet. In other words, when I try to add the characteristic to the service, I end up with a UUID that looks like this: XXXX0001-XXXX-XXXX--XXXX-XXXXXXXXXXXX

This is not what I want. 

Is there a way to add a characteristic with a completely different 128 bit UUID base to a service, without having to add a new service to the gatt table?
I don't want to create 6 different services just so I can have a characteristic with a different base UUID.