What do you mean by "overwrote"? Did you delete and purge the old module? In that case, you will have to revert to a backup of the database.
Or did you just set new values to existing objects? In that case, if you created a baseline, just open it, you might want to use the “smart history viewer“ (http://www.smartdxl.com/content/?p=418). In the case that you overwrote attributes in the current version, it's more difficult. I think there is no script out there that reverts a module to a state some x hours ago.
Perhaps you can write your own script that goes through the history records of the module, like in DXL DOORS Retrieve Redlines from Specific History Version or in http://www-01.ibm.com/support/docview.wss?uid=swg21444153 and with this information display and perhaps restore the old content.
It gets more complicated if you moved, deleted, purged, linked objects in your script