You could create a module called Globals and import it on all your forms, then you can use Globals.x = x to assign a value and x = Globals.x to read it. It will work on any form.
This thread discusses some details about a similar problem.
If you have time to butcher and rebuild your app, this post describes another way to manage the info visible by all the forms in one single variable in the Globals module. It would require tons of restructuring (which you don’t want to do 
) but you would end up with all the info stored in and managed by one global object.