Dynamic assignment of a byte value in a vector in a simulation

SystemVerilog
, ,
1

I pass a parameter from above about which byte from the vector to perform a certain operation on
How can I put a mask on it normally in the Verilog ?
I have it done this way now, but he swears, like it’s done dynamically, but he can’t do it like that

  task force_release(input int num_of_byte);
    begin
      $display("DATA BEFORE = %0h", dut.dut.link_layer.stream_to_header_analyzer.data[0]);
      if(dut.dut.link_layer.stream_to_header_analyzer.data[0][3+8*(num_of_byte-1):10+8*(num_of_byte-1)] != 0)
        begin
          force dut.dut.link_layer.stream_to_header_analyzer.data[0][3+8*(num_of_byte-1):10+8*(num_of_byte-1)]='h0;
        end
      else
        begin
          force dut.dut.link_layer.stream_to_header_analyzer.data[0][3+8*(num_of_byte-1):10+8*(num_of_byte-1)]='hFF;
        end
      wait(dut.dut.link_layer.stream_to_header_analyzer.valid == 1); @(posedge rx_clk_w); #0.1ns;
      $display("DATA AFTER = %0h", dut.dut.link_layer.stream_to_header_analyzer.data[0]);
      release dut.dut.link_layer.stream_to_header_analyzer.data[0];
    end
  endtask

The vector is 67 - bit
The first 3 bits are control bits, that is, starting from the 4th bit in the vector
Now I have this error:
Range must be bounded by constant expressions.

2

I found a solution.This is another form of bit-select

  task force_release(input int num_of_byte);
    begin
      $display("DATA BEFORE = %0h", dut.dut.link_layer.stream_to_header_analyzer.data[0]);
      if(dut.dut.link_layer.stream_to_header_analyzer.data[0][num_of_byte*8+3+:8] != 0)
        begin
          force dut.dut.link_layer.stream_to_header_analyzer.data[0][num_of_byte*8+3+:8]='h0;
        end
      else
        begin
          force dut.dut.link_layer.stream_to_header_analyzer.data[0][num_of_byte*8+3+:8]='hFF;
        end
      wait(dut.dut.link_layer.stream_to_header_analyzer.valid == 1); @(posedge rx_clk_w); #0.1ns;
      $display("DATA AFTER = %0h", dut.dut.link_layer.stream_to_header_analyzer.data[0]);
      release dut.dut.link_layer.stream_to_header_analyzer.data[0];
    end
  endtask