You can do Select, Cut, Copy and Paste operations on text items in Oracle Forms using Select_All, Cut_Region, Copy_Region and Paste_Region commands through right click popup menu.
In this example I created a popup menu which is associated with the both text items and user will do right click on each text item to perform copy paste operations. Below is the screen shot for this example:
I am sharing this Demo FMB file for the reference which you can download through the following link CopyPaste.FMB
Created a popup menu in object navigator and associated the code to each menu option:
For Select_All menu option -- Select_All;
For Cut menu option -- Cut_Region;
For Copy menu option -- Copy_Region;
For Paste menu option -- Paste_Region;
For Paste Sel Txt To --> the following code:
copy_region;
go_item('tgt');
paste_region;