UDT OPCItemPath MODBUS address using 2 parameters

I want to generate a modbus address in the opcitempath using two parameters:

Base address: 40010 (this is the base address that I want to start with)
Instance: 2

The Computed Offset: Instance * 50

The resulting address should be: ns=2:s=chana.deva.40110@Float or ns=2:s=chana.deva.40160@Float for instance 3.

I have tried several iterations of the following opcitempath in the UDT tag

{channel}.{device}.{Base}+{Instance*50} Results: ns=2:s=chana.deva.40010+100@Float

{channel}.{device}.{{Base}+{Instance50}} Results: ns=2:s=chana.deva.{{Base}+{Instance50}}@Float

{channel}.{device}.{Base+{Instance50}} Results: ns=2:s=chana.deva.{Base+{Instance50}}@Float

{channel}.{device}.{{Instance50}+40010} Results: ns=2:s=chana.deva.{{Instance50}+40010}@Float

{channel}.{device}.{Instance*50}+40010 Results: ns=2:s=chana.deva.100+40010@Float

Does anyone have an idea how I can automatically generate the opcitempath using a Base address and an Instance without doing an override on the opcitempath? This will allow us to create a single UDT instead of dozens to poll each instance.

Greg E.