You need to do something like this (Range("A25")
is exactly what you are going to find):
With Range("A25")
.FormatConditions.Delete
.FormatConditions.Add Type:=xlExpression, _
Formula1:="=" & c.Address
'.
'.
'.
End With
and there is no need to write "=" & c.Address & "=TRUE"
, you can use just "=" & c.Address
.