Hmm, well you still haven't told me what you are trying to target. Are you trying to generate a Xilinx FPGA image file, or are you trying to target something else?
To simulate "Xilinx" code with VCS, use the following command line:
vcs -Mupdate -F srcfiles
where srcfiles is a file that has your verilog source files listed in it. An example srcfile:
The 2nd to last line is required for the xilinx global reset function, and the last line is required so VCS finds all the xilinx primitives.
If you are trying to target something other than a xilinx device, you will need to code generic versions of all xilinx primitives that you are using in your design and use those for synthesis (i.e. iobuffers, blockrams, fifo16s, DCMs, etc.)
To find out what primitives are being used, delete the last line in srcfile and look at the error messages when you compile with VCS.