use Win32::OLE;
my $mcd = Win32::OLE->new('Mathcad.Application');
$mcd->{'Visible'} = 1;
my $file_full_name = Win32::GetFullPathName($ARGV[0]);
my $sht = $mcd->{'Worksheets'}->Open($file_full_name);
$mcd->SaveAs($full_file_name, [mcMcad2001i 11]); # this is a guess!
$mcd->Close();