I think my answer to my own question here is the simplest solution to what you are trying to do:
Select the cell where the first line of text from the file should be.
Use the Data
/Get External Data
/From File
dialog to select the text file to import.
Format the imported text as required.
In the Import Data
dialog that opens, click on Properties...
Uncheck the Prompt for file name on refresh
box.
Whenever the external file changes, click the Data
/Get External Data
/Refresh All
button.
Note: in your case, you should probably want to skip step #5.