Help Option In MsgBox?

Hi

I have got the message box to display what i want, and with the Ok and Help buttons, what i need to do is make "OK" return to the user form, and "Help" to display why the message is showing, i also want to make it so the user cant click the close button in the top right corner of the box?

Any Help?

This is my code.....

'//Notify user if entries are missing
MsgBox "Some Fields Are Missing", vbOKOnly + vbApplicationModal + vbExclamation + vbMsgBoxHelpButton, "Warning! Input Error"

Dim iReply As Integer
iReply = "All Fields Must Have Valid Information Inputted, Press OK To Return To Input Part Form"