Not sure if this is what you mean.
We have created a .qvs file and stored on our server. This file contains all of the LET and SET statements to create the variables that we use across most apps. Things like Current Year, 30 days, 90 days ago date.
We then just use an include statement in our script and they all get loaded in the app. The downside is that they get loaded even if you don't use them.