Loading Labview DLL from Python Hits Error

I'm attempting to call Labview defined functions found in a DLL from Python. I based my code on some sample code I found in a white paper. When I hit an error when trying to load the DLL, I tried using the sample code, and that hit the same errror.

Here's the white paper: http://www.ni.com/white-paper/8911/en/

Here's the sample python code provided by NI (simpledll.dll is on the white paper page):

from ctypes import *

#Load the DLL
dll = cdll.LoadLibrary("SimpleDLL.dll")

x = 5
y = 3

#Create sum as a c style integer
sum = c_int(0)
string = create_string_buffer("", 20)

#Function Prototype: int addNumbers (int x, int y, int *sum, char *string)

#Call the Function
#Pass pointers using the byref keyword
returnValue = dll.addNumbers(x, y, byref(sum), byref(string))

#Print Results
print ("Sum: ", sum, "\n")
print ("String: ", repr(string.raw), "\n")
print ("returnValue: ", returnValue, "\n")

This is the error I get when I run the script:

Traceback (most recent call last):
File "C:\Users\trevor.apple\Desktop\TestDLL\CallSimpleDLL.py", line 4, in <module>
dll = cdll.LoadLibrary("SimpleDLL.dll")
File "C:\Python33\lib\ctypes\__init__.py", line 431, in LoadLibrary
return self._dlltype(name)
File "C:\Python33\lib\ctypes\__init__.py", line 353, in __init__
self._handle = _dlopen(self._name, mode)
OSError: [WinError 193] %1 is not a valid Win32 application

I definitely have both files in the same directory, and I've also tried including the full file path to the dll in the load call. Please advise.