How do I restrict an inputbox to 5<= string characters?

I am still new with VBA...

I need help writing a macro that will restrict an input to 1 to 5
characters of the alphabet. This input should be prompted using the
application.inputbox function.

If you are referring to an inputbox on a userform, you set the "MaxLength" property to 5 in the VBE, or if you want to do it programatically, you would use textbox1.maxlength = 5.

If you want, you can also have the focus move to the next control (tabindex) when the max length is reached by setting the "AutoTab" property to true

To restrict only alphabetic inputs use

Private Sub textbox1_keypress(ByVal keyascii As MSForms.ReturnInteger)
Select Case keyascii
Case Asc("a") To Asc("z")
case asc("A") to asc("Z")
Case Else: keyascii = 0
End Select
End Sub

This will allow only upper and lower case letters to be entered in the inputbox.