Hi, it is easy enough to do with a global variable.
I wrote some information about creating and using them here - How to compare global variable value to TextField value
Have a look at it to understand the code below. It is much like setting a rawValue from another field, but instead you are taking it from a variable that can be used anywhere in the form.
To recall the global variable to a textfield:
//give the textfield the value of the global variable.
TextField1.rawValue = global.myVariable;
I wrote this PDF for my own reference, here is a screenshot.
In this example, i can set a new global variable in the first textbox and then recall it in the other when the button is clicked. Same thing applies if you did it from a click, field exit code...whatever.