As far as I know (but i'm quite new in this topic) there is a standard way of setting headers in Varnish that looks like below

set resp.http.X-Custom-Header = "some-value";

But what I really need is a header with dynamic name (or at least part of the name should be dynamic). This dynamic name is based on request or response data. For example I'd like to set/add a header with name "X-Custom-Header-<dynamic_part>" where <dynamic_part> is simply value from variable. The upshot should be like

X-Custom-Header-test1: someValue;

In other words I'd like to set header where it's name is a string

Any idea how to do it? (I know of headerplus module but it's available only in Enterprise version)