How to modify DOSBox settings when used in conjunction with Glidos?

I am trying to run "Grand Theft Auto" on Win7 x64, but it won't work.

Glidos mounts "C:\GTA\gtados" to "C:\", and then GTA won't load because it wants to access "..\gtadata\player_a.dat" on startup (which is not accessible because of the way you're mounting the directory).

Also it mounts the first Disc-Drive it finds to DOSBox, which is the wrong one in my case.

So how can the DOSBox settings modified when using Glidos?

When I manually mount the GTA directory (MOUNT F "C:\GTA"), and I try to run gtafx.exe, the game won't work either.
First the text on the screen turns from gray to white, then the screen gets black and nothing further happens.