@slepagetrudeau if you could upload the logo image to the web, this Python method to save the image in the user’s temp folder might work for you:
Python script:
import sys
sys.path.append('C:\Program Files (x86)\IronPython 2.7\Lib')
from urllib import urlretrieve
url = 'http://dynamobim.org/wp-content/themes/dynamo/img/icon.png'
file = 'C:\TEMP\logo.png'
urlretrieve(url, file)
OUT= file
The first 3 nodes could be bundled into a custom node to make it cleaner for adding your logo to graphs 