Before IIS6 you need to access the metadata in IIS configuration via IMSAdminBase::GetData. The hard part to find the path of the IIS setting. Before IIS 6, the metadata isn’t saved in XML. However you can search the path of a property though the admin script. You can find the path property from the IIS metadata propertiy reference documentation.
The IIS WMI provider, introduced in IIS6, makes the query a lot easier. Now you can query for IIsFtpVirtualDirSetting.Path directly, though querying metadata should still work.