Subscript and Inches in Custom Formats

I have been searching all over Google for this information. All I find is superscripts and stuff that is not accomplishing what I am needing.

I want two custom formats.

1) 0.00" """ Hg" - to display as |0.15 " Hg|
Currently I am dealing with 0.00" in. Hg" - but I want the inches symbol instead of in.

2) 0.00" """ H2O" - to display as |0.15 " H₂O
Currently I am dealing with 0.00" in. H2O" - but I want the inches symbol and the subscript 2 because chemical equations are annoying. I know Alt+0178 is a superscript; but I cannot find anything about subscript.

Perhaps this file could be of help?

Original work was done by ChemistB I think and I modified it a bit to suit my needs so all credit goes to ChemistB.

Alf

Ps Old chemists don't die they just fail to react

It took awhile but I found a workaround. Inserting ' twice would replicate " - simple stupid.

For some reason, finding a subscript character and copy+paste into the custom format.