Multi-dimensional array of UDT's

I’m using 7.6.6

There is a multi-year, 365-day calendar in an encrypted PLC with totals for various things. I need to access today and yesterday from this calendar.

The array is multi-dimensional, covering year, month, day. The data for today (0-based) looks like:

[Device]Totals[0,7,25].v0
[Device]Totals[0,7,25].v1
[Device]Totals[0,7,25].v2

How can I do this? I keep running into “illegal tag path” whenever I try to form a tag path string.

I’m using 7.6.6.