How to deal with the tempary coefficient in the FPGA design

In my FPGA design, I need a result of EXP(z: is complex) as a tempary coefficient for other calculations. I've known to deal with the real part and imagin part separately. But I don't know how to deal with the floating point numbers. I only managed to deal with the easy floating point things, e.g. 2**(-A), A is an integer. I don't know how to deal with the tempary coefficient in the floating point type in the FPGA design. Does anyone here has the similar experience to deal with floating point as the tempary coefficient in the FPGA design? Can tell me some tip about this? Thank you.