The function to copy paste between different modules is already there.
Just open two different modules, select an action and copy/paste from the edit tab.
However it is not possible to multiselect or copy the entire module and copy paste, the way i to do to fix this issue is make an IF statement and put all the module actions within it, And then copy/paste so that it acts as a single action.
If you want to use all variables from other module to another module. You can just copy this module. And then edit this module to what you want.
Check this post to know more details: http://www.whitehatbox.com/bbs/BBSPost?fid=17&postid=1905&pid=2#.WOxPE6IlEdU