private string GetCountryResourcePath(string countryName)
{
Assembly assembly = this.GetType().GetTypeInfo().Assembly;
string[] assemblyResources = assembly.GetManifestResourceNames();

string searchTerm = string.Format(".{0}, countryName);

foreach(string resourcePath in assemblyResources)
{
    if (resourcePath.LastIndexOf(searchTerm, StringComparison.OrdinalIgnoreCase)>0)
        return resourcePath;
}
return string.Empty;
}

string countryResourcePath = GetCountryResourcePath( countryName );
if (countryResourcePath == String.Empty)
    return;

using (Stream countryStream = assembly.GetManifestResourceStream(countryStream))
...