define task conversion in verilog

I have this code.

`define test(VAR)\
pkt.VAR = VAR

But I want to convert this to task.

task test(string VAR);
pkt.VAR = VAR;
endtask

When I change this, I got error message when compiling: VAR is not a class item.

I think VAR is different for define and task.

How can I convert above define to task?