VBA EXCEL - NUMBERFORMAT didn´t work but FORMAT FUNCTION did

Question

I have a range of cells named MyCells as string type. In which there are strings with 26 digits.

Why the first statement (below), with NumberFormat didn´t work, but the second did?

Trying cells look like this:

38935094000163001000052234 --> 38.935.094/0001-63 001 000052234

First attempt (didn´t work):

range(MyCells).Select

Selection.NumberFormat = "00"".""000"".""000""/""0000""-""00""   ""000""   ""000000000"

Second (successful):

range(MyCells).Select

For Each c In Selection
    c = Format(c, "00"".""000"".""000""/""0000""-""00""   ""000""   ""000000000")
Next

Solution

"The Format function uses different format code strings than do the NumberFormat and NumberFormatLocal properties." from http://msdn.microsoft.com/en-us/library/office/aa224873%28v=office.11%29.aspx.