You can't.
If you need any sort of special InputBox you will have to make your oun,
using an unbound form with whatever controls you wish to place on it.
Add a Command button to the form.
Code it's click event:
Me.Visible = False
Then, in your code, instead of using
strText = InputBox(etc)
you would use:
DoCmd.OpenForm "FormName", , , , , acDialog
strText = forms!FormName!ControlName
Docmd.close acForm, "FormName"
