Creating a microvia with Pad_Designer 16.5

Hi everyone,

I have a .4mm pitch BGA that will be included on my next design, so I'd like to get set up to use microvias.  I thought I could edit the dimensions of an existing thru via to make it a microvia in Pad Designer, but under Parameters/Usage options in Pad Designer, the Microvia option is greyed out.

Am I trying to do this the wrong/hard way?  For what it's worth, I'd like to make a 10mil pad with a 4 mil drill for my microvia.

Maybe a better way to ask the question: How do I make a microvia padstack in PCB Designer 16.5?

Thanks in advance for any help.  Best Regards.