It should work with Julia or any scripting language just fine. Simply write the following two lines in your block "run.meta" file
-----------------------------------
julia
script-name.jl
-----------------------------------
and this should run your script.
The path to "julia" must be in your system $PATH variable or in the search path in the settings menu of pxWorks.
The platform supports any scripting language
You can let me know if you need help using this link