Macro to pause for user input in dialog box

[Guest]

I have a macro that i want to select a 500 cells, go into the Data Validation
menu, and then pause so that the user can input their particular validation
parameters and the input message. Then when the use hits OK, I'd like the
macro to continue on it's way. Here's what I have, but it just selects the
cells and doesnt open the dialog box.
Application.Goto Reference:="R1C3:R500C3"
With Selection.Validation
.Delete
.Add Type:=xlValidateInputOnly, AlertStyle:=xlValidAlertStop,
Operator _
:=xlBetween
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = ""
.InputMessage = ""
.ErrorMessage = ""
.ShowInput = True
.ShowError = True

Any help with explanation is appreciated as this is a feature I'd like to
use in several different scenarios. Thanks.

 

[Guest]

You can everything within the With clause with
Application.Dialogs(xlDialogDataValidation).Show