I'm confused, I need more info. Are you expecting different numbers in your textbox input and therefore trying to separate (parse) them into individual number data? Or are you trying to use a number typed into a textbox as a global value. If it is the latter I would do this:
TextBox: On text changed > System: set "GlobalVariable" to int(trim(TextBox.text))
int() changes a string into an interger and trim() makes sure you didn't accidentally hit the space bar. You can also change to condition to when button clicked if you want to wait for the full number to be typed in.
If this has not answered your question, please give an example of what you are trying to do.