custom format help (leading decimal pt and Inch mark)

I don't think a custom format option is possible for this.
How could format know that 432 should be 0.432 and 132 is to be 1.32?
Both are the same length.

If possible, enter all of the 0.xxx numbers in a column (straight entry, general format)
do the same for all 1.xx numbers.

Afterwards, for all 0.xxx numbers enter a value of 1000 into a blank cell, copy the cell, the highlight the target column (all cells) and perform a Paste Special > Divide.

Do the same for the 1.xx cells but use a factor of 100.
No need for a helper column with this approach.

If you plan of using these values for analysis, then omit the double-quote character which will cause Excel to view the values as text and thereby prevent calculations with the data

There are two seperate reports,
For the first one I have a solution:

Drop this into the CUSTOM FORMAT area Without the ( )
("."#[$"])

Still not sure how to get the other one to work....

It is only a three digit input

Specifically wanted to avoid the formula solution as the users in my office would eventually mess it up and print the wrong block of data.