Excel OLE Automation using COM: file access problem

Hi, I am interfacing PHP and Excel to build a web-based reporting tool. I am running IIS6.0 with PHP 5.2.5 on Windows Server 2003, with Office 2003 installed. For testing purpose, I wrote a script that just connects to Excel, opens a workbook, saves it under another name and closes Excel: $if_path = 'C:\if_test.xls'; $of_path = 'C:\of_test.xls'; echo date('H:i:s') . " Launch Excel application \n"; $excelApp = new COM("Excel.Application") or die("Cannot create an Excel object"); echo date('H:i:s') . " Loaded Excel, version {$excelApp->Version}\n"; echo date('H:i:s') . " Open workbook at path $if_path\n"; $excelApp->Workbooks->Open($if_path, 2); echo date('H:i:s') . " Save changes to $of_path\n"; $excelApp->Workbooks[1]->SaveAs($of_path); echo date('H:i:s') . " Close Excel\n"; $excelApp->Quit(); When I open the page in Internet Explorer, if I put "http://localhost/test.php", everything works fine, but if I put "http://my_server_name.domain.int/test.php", the script is blocked when trying to open the file, which means I can't access the script elsewhere than on the server. By "blocked", I mean no error is shown, but it doesn't react, and the excel.exe task keeps running and keeps the file locked. My guess is that Excel is run with different permissions in the second case, so it cannot access the file, but it might be completely something else... Does someone have any experience in that matter ? Thank you very much !