If you are new to VBA, this is going to be a challanging learning experience.
In the code you downloaded is a function named GetOpenFile. You can
experiment with it to see what it will do. To do this, in your immediate
window, type in x = GetOpenFile(). You will then see the Common Dialog box
where you can select a file. Once you have selected the file name, type in
?x Then you will see the full path and name of the file you selected in the
common dialog box.
Now, using that to import the files you want:
Dim varGetFileName as Variant
varGetFileName = GetOpenFile()
If varGetFileName <> "" Then ' An Empty string means the user canceled.
DoCmd.TransferText, acImportDelim, ,"MyTableName", varGetFileName,True
End If
You will need to insert your own table name and whatever arguments you need
for the transer.
With a little reading and study of the code you downloaded, you will see
that it is possilbe to identify the default directrory to look in for the
file name, and the default file name.