Im guessing you have to use .NET Framework which no one has taken into account. If this is the case, "Changing your User Agent" will have no effect. If your company has many apple users, I would suggest you talk to your System Administrator and ask him about Remote Desktop Services (formally known as terminal services). This way apple users can log onto a remote instance of windows to access the database. All of the Virtual Machine softwares will bring your computer to its knees. If you are using remote desktop services, the remote computer is responsible for a processing requests.
EDIT: And just to clarify, if it does require .NET Framework, no software can emulate that. i.e. wine, crossover.