Software Deployment

Ok here is my scenario.

I have most of my users computers installed with Office XP Professional. Some users already have Office 2003 Standard installed manually.

I want to assign the office 2003 standard package via GPO to all my users. Here in lies the problem.

For office XP computers, Office 2003 standard does not uninstall Access XP, since it's not replacing it. (Even when choosing remove all previous versions in the MST file) I need to know how, using the Custom Installation Wizard, I can get it to remove Access XP as well.

2nd problem is, for computers with Office 2003 standard already installed, the GPO will install the managed software version of office 2003, leaving the other version on there. What I mean by that is, if I delete the software package from the GPO, and instruct it to uninstall from users PC's, it will remove the managed version, but the original office 2003 software is still installed and can still be used.

Sooo, also is there a way via the custom installation wizard, or anything for that matter, to UNINSTALL OFFICE XP PRO & Office 2003 Standard, BEFORE the GPO installs the assigned software.

Any ideas?