how to set environment variable to use in loadtestrunner

Hi, 

i am trying to read an environment variable in a groovy script:

def host = context.expand('${#Env#API_HOST}')

i set the environment variable:

export API_HOST="https://api.host.com"

when i run: 

echo $API_HOST

i get: 

https://api.host.com

when i run the groovy script from soapui:

log.info context.expand('${#Env#API_HOST}')

i get null or an empty string.

when i run loadtestrunner with a step including: 

def host = context.expand('${#Env#API_HOST}')

the host is still empty.  

any idea on how i can resolve this?

am i setting the environment variable correctly?

am i trying to access the environment variable in the groovy script correctly?

any more info i can provide?

thanks a lot.