...
> How do I keep the leading zero when I dereference the variable?

You need to ensure that the variable is treated as a string by the CI.
This can be done by enclosing it in quotes, or using it as a parameter
to any CI functions that expects a string.  E.g.
   :setvar x "0119"
   :calc typeof(x)
   2   %2   $2     <<string>>

   :setvar y x
   :calc typeof(y)
   2  <<still a string>>

   :setvar y !x
   :calc typeof(y)
   1  <<int>>

   :setvar y "!x"
   :calc typeof(y)
   2  <<string again>>

HTH,
Jeff Vance, CSY