Data corrupted during pasting

When I paste into Excel 2008 data copied from a table in an HTML page, Excel corrupts the data by interpreting it: for instance, it arbitrarily replaces "12-34" by "Dec-34". If I change the cell format to text, it replaces it by "12754", the value for December 1st 1934!
I tried setting the cell format to text before pasting, but this is overridden by the paste operation. If I use Paste Special using text format, I do get "12-34" as wanted but I also get all the rest of the row in the same cell, as Excel no longer recognises the separators! How can I tell it to stop try and be clever and just copy the text as it reads it?