If your Panther is on one DVD the XCode installer may be on the DVD I believe. If it is on 3 CD's the XCode installer is on a separate CD, #4. Even if you have it you'd probably want to make sure you had the latest for Panther anyway, it can be downloaded from here.
They are also the latest versions. They are big downloads.
You can download from a PC but you'll have to get the big dmg to the Mac somehow. You'll need to register an ADC user name to get access to the link and downloads. After logging in go to Downloads, then click on Developer Tools on the right. Scroll all the way to the bottom. You'll need to get Xcode Tools v1.5 for Panther. I don't know if you'll need to install v1.2 or v1 before installing Xcode Tools v1.5, can't remember for sure but I think all you'll need is Xcode Tools v1.5 so try it first.