A script for this is on the wiki:
http://wiki.mikrotik.com/wiki/Using_Fetch_and_Scripting_to_add_IP_Address_Lists
However, it does not work with your IP list because the file size is 17500 bytes. Currently there is a file read/write size limit of 4K (4096 bytes):
http://forum.mikrotik.com/t/save-export-to-variable/36882/3
I deleted a bunch of lines in your text file (getting the file down to less than 4096 bytes), and then tried the script. I tested this in RouterOS 5.7, and I had to fix the comment line that says: “#If the line doesn’t start with a hash then process and add to the list”. It was causing errors, so I just deleted it, and then the script worked fine.
One problem I noticed with the script is that if the last IP address in the text file will not be read unless “\n” (a new line) has been detected. So, if there is not a new blank line at the end of the text file, you’ll be missing the last IP address.
If you can break up the IP list and send it in parts, you should be set.