Importing exporting data file in mathcad problem

Hi, help me please, i have two mathcad files(for example: a.xmcd, b.xmcd) in a.xmcd i have one number and i export this number in 1.txt file, in b.xmcd file i import that number from 1.txt and i use it to resolve one ecuation, result i export in 2.txt file and from 2.txt i import in a.xmcd file, it works, but i have one probleme, every time i change this number i must restart both mathcad files so the ecuation can be solved with new number. How can i do this with avoiding restarting mathcad files.Don't ask why a need this .Sorry for my english.