If you are using Windows 10 and the key presses are not being emulated, try downloading the Win 10 Saitek x52 pro beta drivers here and the windows 10 beta software here. The Madcatz software is needed to bind the control profile to the HOTAS. The mappings themselves are set using the default keyboard mapping in Star Citizen, so if you have changed those controls, this will not work properly. Here is an album containing pictures of each mode's key mapping.
The axes and MFD buttons have to be programmed withing SC in the joystick section, since they can't have buttons bound to them, and therefore do not change function with the mode.
The three modes are Combat, Power, and Travel. It uses all three modes on the joystick, changeable with the three step dial on the stick. Here is a key mapping for the X52 Pro HOTAS I made. Edit: Sorry, I thought the post link would go to the link I copied, guess I accidentally made it a text post.