bryan (not brian),
use the examples named etherccm (there's one for visual basic and one for visual c). it demonstrates the basics of locating the ecom or ecom100 on the network, establishing a connection to it, readng and/or writing data, then closing the connection.
that example lets you read and write plc data by manually entering the range, length, etc. and sending the output to the screen. in your app, you'll need to replace the ui so that your application will enter the required data, and replace the output code so the output data goes to a file instead of the screen. both of these should be pretty straight forward.