text to date in excel

have an excel sheet containing a summary of a lot of word file, tables data which has been cut and pasted into excel

most of the data is fine to filter and pivot, ...  but one column of this data is a 'date column' entered in word as 12.10.09 format.  this will not convert to 12-OCt-09 using the format option in excel.  my question therefore is how to convert this colunm into the required date format  ie from 12.10.09 to 12-oct-09

many thanks