passing IRUN command-line arguments into vsif file?

Hi,

I use command-line arguments in my script and it looks like this

irun ... +define+MY_ARG ...

I can run stand-alone simulation with different MY_ARG to different tests.

How can I reuse my script in a vsif to launch regression of all tests? Is there a way to define an attribute so I can specify MY_ARG in vsif, for example

...

test my_test1 { my_arg_attr : 2};

test my_test2 {my_arg_attr : 3};

... 

Thanks for help.

Xing