Solution : https://service.sap.com/sap/support/notes/302319 (SAP Service marketplace login required)
Key words : 
additional key words sapscript, transfer protected text lines, change locked text lines, locked text lines separated, locked text lines, sapscript pc editor, choosing goto -> editor, text editor, text consists, continuous text
Related Notes : 
       
| 396958 | SAPscript: Inserting Clipboard deletes locked text lines | 
| 363243 | SAPscript: Collective note for template lines | 
| 337373 | SAPscript: copy locked texts to clipboard | 
| 305856 | SAPscript: Locked text lines deleted | 
| 302655 | SAPscript: Clipboard overwrites locked texts | 
| 216488 | SAPscript: Incorrect format of locked rows | 
| 215591 | SAPscript: Deletion of locked lines in PC editor |