The poster asked for text boxes not cells.
Putting things in all caps that should not be in caps is about as
unprofessional as you can get for an appearance.
KB 152379 - How to Copy the Text Within a Text Box to a Cell
http://support.microsoft.com/?kbid=152379
( you can Google kbid=152379)
Here is a regular macro to change text to all capitals in the textboxes
of the active worksheet.
Sub KinderTextboxCaps()
Dim tbox As TextBox
For Each tbox In ActiveSheet.TextBoxes
tbox.Text = UCase(tbox.Text)
Next tbox
End Sub
This is an Event macro (install with right on sheet tab, view code, ...)
that will change to caps upon selection of the worksheet.
Private Sub Worksheet_Activate()
' change all textboxes on the page to caps
' upon worksheet activation. DMcR 2004-07-15
Dim tbox As TextBox
For Each tbox In ActiveSheet.TextBoxes
tbox.Text = UCase(tbox.Text)
Next tbox
End Sub
has been added to:
InputBox, MsgBox and TextBox
http://www.mvps.org/dmcritchie/excel/inputbox.htm