I'm not sure about VB but in Delphi/C++ there's a property that controls whether to automatically select all the text inside the control when it gets the focus or not.
If there's no such property in VB for this control then you can create an even handler for OnFocus event for one text box and then assign it to all controls on your form that have the same class name by scanning form's components array in form's OnCreate event.
4-5 lines of code will take care of this whole thing.