In windows you can do the following in your system variables

set FOO=SomeValue

set PATH=%PATH%;%FOO%\SomeFolder

windows will expand to

PATH -> ...;SomeValue\SomeFolder

I use this for QMAKEFEATURES

However in the qtcreator the value for QMAKEFEATURES is

%OA%\bin

which should (in my case) expand to (or be expanded to)

c:\data\OARuntime\bin

but it does not

Manually changing the build environment variable to the value above makes things work but that means that ever project I make that depends on the same feature files will need to be manually updated -> tedious and error prone !