A couple of things:

my @args = ("c:/glomosim/bin/","data.in");
[download]

Here you provoide a directory, but not the name of the executable you want to call. Also if you have the data.in file within the bin directory you'll need to do:

my @args = ("c:\\glomosim\\bin\\glomosim.exe","c:\\glomosim\\bin\\data
+.in");
[download]

Note that in both occasions I provide the full path to the file, and use \\ rather than / as the path separator. As a piece of general advice, the easiest way to get help with errors is to post the erros along with the code which generates them. How do I post a question effectively? has some great advice on posting. Let me know if you have further problems

Thank you, you are really helpful. But I do not want to run glomosim.exe , what I want is to run the command (glomosim data.in) on CMD.exe ! So I tried to write :

my @args = ("c:\\Windows\\System32\\cmd.exe","c:\\glomosim\\bin\\data.
+in");  
       system(@args) == 0 or die "system @args failed: \n syscode:$? \
+n error:$! \n";
[download]

but I get nothing !! Microsoft windows version ..... etc ! How I can pass a command (glomosim data.in) to cmd.exe ? Thank you very much.

Don't worry about it, we're here to help. The weirdness you're seeing "Microsoft windows version..." is the output of running cmd.exe. If you did a Start->Run->cmd.exe then you'd see something like:

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\marto>
[download]

What you want to do with system is run a comand called glomosim, and pass an input file. So the first part in the example I gave you was to a program called glomosim.exe, if this isn't an executable you need to substite the command with whatever you want to run, not cmd.exe, so the general form of what you want to run is:

my @args = ("c:\\path\\to\\glomosim","c:\\path\\to\\input.file");
[download]

So you need to substite the path to the golomsim program and the path to the input file in the above example. In Re^2: system sub routine with windows7 I give some code to use to produce any errors. I have no idea what glomosim is, how it's executed, but if you substitute these values for the correct paths to the executable and input file we can provide further help if required.