I am unable to import the MOSFET models from the Infineon site. The library file can be downloaded from the Infineon site: OptiMOS™ 5 80V/100V - Infineon Technologies
The .lib file contains several subckts. There is no way to create a symbol for one of the subckts if I copy paste the content.
For library with several sub-circuits, you can call that library from subckt symbol.
A quick way to use a level 0 model from infineon OptiMOS is to take advantage from NMOS symbol. This is an example of a dc sweep for IAUTN06S5N008 level 0 subckt in OptiMOS_5_60V_LTspice.lib
highlight the procedure to convert NMOS symbol into a subckt
dc sweep simulation compares to datasheet