Modbus TCP / multiple variables and data formats

This is very good Project! I started to work with this programm. As an begginer I cannot find two data formats that I need for my Modbus variables'definition:
— u64 — unsigned 64-bit (4 registers)
— s64 — signed 64-bit (4 registers)
How can I set this type of data?

Also I have another question. Can I define reading schema for reading of one device with multiple variables in text redactor or in excel and after this to import the parametrization data into the programm? Can I save parametrization and copy/paste for multiple devices?

Good luck with project!