Excel VBA Runtime Error 13 - Type Mismatch

Hi all,

I have a VBA script which is designed to conditional format certain cells based on another cells dropdown selection however every time i run it i get the runtime 13 error. Now i know the formula is a big one within this macro however i've been told this is the only way I can get excel to conditionally format using this formula. Can someone help?

I am using excel 2003 if that helps anyone. Thanks

Sub format()
'
' format Macro
' Macro recorded 30/07/2013 by James Pite
'
' Keyboard Shortcut: Ctrl+e
'
    Range("D14:AZ20").Select
    Selection.FormatConditions.Delete
    Selection.FormatConditions.Add Type:=xlExpression, Formula1:="=AND(D$4>=VALUE(LEFT(INDEX($D$57:$AA$63,MATCH($C6,$C$57:$C$63,0),MATCH($A$13,$D$56:$AA$56,0)),FIND(" - ",INDEX($D$57:$AA$63,MATCH($C6,$C$57:$C$63,0),MATCH($A$13,$D$56:$AA$56,0)))-1)),D$4<=VALUE(MID(INDEX($D$57:$AA$63,MATCH($C6,$C$57:$C$63,0),MATCH($A$13,$D$56:$AA$56,0)),FIND(" - ",INDEX($D$57:$AA$63,MATCH($C6,$C$57:$C$63,0),MATCH($A$13,$D$56:$AA$56,0)))+1,255)))"
    With Selection.FormatConditions(1).Font
        .Bold = False
        .Italic = False
        .ColorIndex = 1
    End With
    Selection.FormatConditions(1).Interior.Pattern = xlNone
End Sub

I have asked this question on another forum which can be found here