Verilog Barrel Shifter

Question

I want to create a 64-bit barrel shifter in verilog (rotate right for now). I want to know if there is a way to do it without writing a 65 part case statement? Is there a way to write some simple code such as:

    Y = {S[i - 1:0], S[63:i]};

I tried the code above in Xilinx and get an error: i is not a constant.

Main Question: Is there a way to do this without a huge case statment?