Yes it is possible and quite an easy operation in DataDynamic Reporter.
First of all, after you opened the desired .ddf2 file:
+ open one of the .ddo files and when displayed delete all the tables you'll not need
+ click on 'Open ddo' again and open another .ddo file. Before tables will be displayed a pop-up window will appear (see picture)
Click 'Yes' and Tables will be appended below the ones you kept at the step before.
+ Again delete the unnecessary tables and proceed by repeating this step until you have collected all your desired tables from the different .ddo files.
+ Don't forget to 'Save DDO' by hitting the proper button.
NB: Before to make this operation make sure to verify every table you'll need to keep in your newly created .ddo file, will contain variables available in the .ddf2 file used. This variable needs to be the same in the ddo and ddf2 file.