Your safest way is going to be with a little shell script. If you have the vis command it's probably better than cat -v. I don't know if these files are parts of a binary or text file. The general script would look something like this. The redirection I do is for a good reason. cat -v a1 a2 a3 a4 a5 a6 a7 a8 a9 >>afile. The first line of the script would be #!/bin/sh. That longer line I wrote earlier would be duplicated as many times as necessary and you'd change the numbers each line down the script. so that the last line in the script would be cat a91 a92 a93 a94 a95 a96 a97 a98 a99 >>afile. If you use a command like .,.s/a[1-9]/a1[1-9]/gp <cr> That should change line 3 in the script from cat a1 a2 a3 a4 to cat a11 a12 a13 a14 etc. Jude <jdashiel@shellworld.net>