[Exim] Is it possible to get environmen variables?

Does Exim provide us a measure to get value of environment variable in the configuraion file?

That say:
Standard:
...
smtp_daemon_port = 25
...

Environment:
In the shell:
export SMTP_PORT=25
In the Config file:
...
smtp_daemon_port = ${env SMTP_PORT}
...

Hunte