Can you set a name to refer to the value of a textbox?

In reference to the Name Manager. Can you set a name to refer to the value of a textbox or downdrop?

What I'm trying to do is I use the one value in my data sheet combined with the OFFSET function to select the number in a range I want to graph. Instead of using 1 box to control the range for 10 graphs, I want the user to be able to change it easily on a graph only sheet without interacting with the data which I want hidden.

Any other suggestions if you can't do what I want?