VBA - How to linking text box value with another text box

Could someone tell me if it's possible to link the values of different text boxes in Excel?

Root cause: since Excel doesn't allow different column widths for different rows in one sheet (without merging cells), I had to use some text boxes as input area in a workbook. 

The purpose is: if I input certain content in Text Box 1, the same content will automatically appear in Text Box 2 as well, so that I don't need to input twice the same content.

Since I know little about VBA, my trials have failed many times. This seems much more difficult than linking the text box value with a cell, but I believe there are people who know how to manage...