Just create a windows batch file (file.bat) and stick the nslookup calls in to it. You can copy/paste and write the results stdout/stderr to a file and wait while it processes. If you only have a windows machine and no software development environments this is probably your easiest bet:
That will put all of the contents in to results.txt. Just copy/paste your hostnames then get "nslookup " on your clipboard and paste down the left side, then make one more pass at the file and hit the right side.