In Release 4.5A, you can define in your planner profile whether you want to enter your plan data in a traditional planning layout as before or in an Excel spreadsheet. If you choose the latter, the R/3 System integrates this Excel spreadsheet directly in the user interface of SAP's R/3 System (the so-called "SAP-GUI").
You can define an Excel master spreadsheet in Customizing to determine the layout of this spreadsheet. This master forms the link to your plan data in CO-PA, and can contain special formatting, graphics, or other macros.
Once your plan data appears on the screen, you can process it using both the planning functions of CO-PA and the flexible functions of Microsoft Excel. Moreover, you can save the planning documents that you process using Excel on your local hard drive, and process them again later there using Excel. Once you have finished entering that plan data, you can then upload it into the R/3 System using the flexible upload functions, and then process the data further using the functions of CO-PA planning.