Creating a popupmenu or file selection box with associated values

I am looking to use GUI controls to create a drop down or file selection box that has specific variables from the worspace generated from the rest of my code and then when a specific drop down is selected it will show the value of that selected variable in a static text box in the same figure as the control.

[Walter Roberson]

Which workspace do the variables live in?

sharing variables

[Joseph Mazzella]

The variables are currently in the base matlab workspace.