If I use QSpice to create a new symbol, How do I associate a schematic below that symbol?

[KSKelvin]

You mentioned the tunnel diode symbol in another thread. Here is an example using a subcircuit symbol to obtain a model from an external library file.

example.TunnelDiode.1N2927.qsch (41.8 KB)
Tunnel Diode Library - Bordodynov.txt (1.2 KB)