HOCON conditional substitution with surrounding text

I have no way currently to test this syntax myself, thus the question:

Will substitution/overriding of a value still happen if it's surrounded by text?

For example, I know that:

foo.baseUrl = "http://foo:1234/" foo.baseUrl = ${?FOO_BASE_URL}

will overwrite foo.baseURL if the ENV var FOO_BASE_URL exists.

What happens here?

foo.baseUrl = "http://foo:1234/" foo.baseUrl = "http://${?FOO_BASE_URL}:1234/"

does the override still happen if the ENV var exists? does putting it within a string negate this?