I had a similar problem where I needed to copy data files from a folder in my project folder (\data\) to the \bin\debug\ folder.
This is what I used.
From the tool bar open: "Project -> Build options -> [project|target] -> Pre/Post build steps"
In the "Post-build steps" text box put : cmd /c copy ".\data" "$(TARGET_OUTPUT_DIR)\data\"
In my case, this will copy all the files from \data into \bin\debug\data.
Remember to create the folder you want to copy the files into (i.e. the \bin\debug\data folder) otherwise it causes an error.
Also, check the "always execute, even if target is up-to-date.". It helps when you're editing the "Other" files and re-testing but not modifying the source files.
Hope this helps