Note: CAL (ClearCase Automation Library) might not be available for the latest versions of ClearCase (8.x): it is for CC7.1.2 or less.
Since you can execute cleartool command with it, your best approach is to first check if you can get the data you want through cleartool script, and then reporting that script in a CAL script:
my $cal_ct = Win32::OLE->new('ClearCase.Cleartool')
or die "Could not create the ClearTool object\n";
my $cclsvob = $cal_ct->CmdExec('lsvob');
For reading data of any version without any checkout, you need to search in a dynamic view, where you can read any extended pathname (see "About the version-extended path").
For finding your file, you need a cleartool find
command, with the option -nvi/sible
:
Includes only those elements, along with their branches and versions, that are not visible (do not have a standard path name) in the view.
cd /path/to/view/AVob
cleartool find -all -name "myfile.txt" -nvis -print
Then you need to cat the %CLEARCASE_XPN% result
cleartool find -all -name "myfile.txt" -nvis -exec "type \"%CLEARCASE_XPN%\""