Is there a platform independent way to use "${ENVVAR}more_text" in vim?

Question

I just discovered that I am able to use ${ENVVAR}more_text in a vim installation on Unix, but not if installed on Windows.

In Unix, I did in a shell:

export ABC=/tmp/
echo foo>${ABC}foo
gvim

Then, in the newly opened gvim Window, I tried

:e ${ABC}foo

which opened /tmp/foo, as expected.

In Windows, however, I did (cmd.exe):

set ABC=c:\temp\
echo foo > %ABC%foo
gvim

then, in gvim

:e ${ABC}foo

which opened a (non existing) file literally named ${ABC}foo (which is not what I expected).

Is there a way to have vim expand the expression ${ABC} on Windows as well, or an equipotent alternative?

I realize, that for this simple example, I could define the environment variable without trailing slash and add the slash in the :e command while not using the braces at all. Yet, I want to achieve something more complex than that so that I fell I sort of need the ${ABC} construct.

Edit

As per murus comment: in Windows, after starting gvim, if I do echo $ABC, gvim prints c:\temp\.

Answer 1

I tried to use backtick expansion, but that does not seem to be working on Windows. So I think the easiest solution is something like this: :exe ":e" $ABC."foobar.txt"