Does the range have to be on Lists in the workbook with the code?

Dim myRng as range
dim myRngC as range
dim Cell as range

set myRng = nothing
on error resume next
set myrng = application.inputbox(Prompt:="Select a range",type:=8)
on error goto 0

if myrng is nothing then
  exit sub 'user hit cancel
end if

if myrng.parent.range("a1").address(external:=true) _
  <> thisworkbook.worksheets("lists").range("a1").address(external:=true) then
   msgbox "Please select a range on Lists in: " & thisworkbook.name
   exit sub
end if

set myrngC = nothing
on error resume next
set myrngc = myrng.cells.specialcells(xlcelltypeconstants)
on error goto 0

if myrngc is nothing then
  msgbox "no constants in that range!"
  exit sub
end if

for each cell in myrngc.cells
 'do your stuff.
 ....