Spread如何在某个单元格绑定一个字符串

我想在Spread的某一单元格绑定一个字符串，使得用户无法看到？我采用批注的方式实现的，但是用户能看到批注的标志。请问该如何让用户看不到？谢谢！

Cell.Tag
Gets or sets an application-defined tag value for a cell.

Cell.Tag最多能存储多长字节的值？

这个Tag是string类型的。没有特别规定长度限制

文档上说

The tag is only for the application's use; the spreadsheet does not use this information in working with the data. The information in the tag is stored separately from the information provided in the text or the value or the note.

You can assign user-defined information to any cell, column, row, sheet, or the entire component. The information in the tag is not composited from these different levels.

我是需要导出到Excel里的，并将相应的值绑定到excel里。我试过了，这种方式实现不了。