There is another (somewhat easier) solution, without the size problems. I used this approach today (on a 2003 XLS file, using Excel 2007) and was successful.
DPB=...
partDPB=...
string to DPx=...
*NOTE: Be sure that you have changed the password to a new value, otherwise the next time you open the spreadsheet Excel will report errors (Unexpected Error), then when you access the list of VBA modules you will now see the names of the source modules but receive another error when trying to open forms/code/etc. To remedy this, go back to the VBA Project Properties and set the password to a new value. Save and re-open the Excel document and you should be good to go!