Run the program w/o opening a cdb
I.e. see if you can load all the database commands (just comment out actually using them)
If this works, you actually have a problem opening the file, not accessing the commands.
Put the cdb in the current working folder of your program and skip the entire path
Using a regular string instead of a verbatim (skip the @ and use escapes for the slashes \\) like the examples.