Logstash export variable

I have one property file where I have mentioned the HOME path. I want to input this property file in logstash input and then use it in the filter.

app.properties:

export HOME="C:/Users/ankitamishra2/Desktop/Elastic_v1/sources/log/*.txt"

logstash.conf:
input {

        file {

        type => "text"

        path => "${HOME}"

                                start_position => "beginning"

                                sincedb_path => "C:/Users/ankitamishra2/Desktop/Elastic_v1/sources/sincedb/logdb/sincedb-access"

                                stat_interval => 1

                                codec => multiline {

                                pattern => "^\s"

                                what => "previous"

                                }

                    }

output {
stdout {
codec => rubydebug
}
}

Any idea?