What are you trying to convert it to?  Spectre's VCCS has min and max parameters that should deal with what you have.

I'm a little confused by the subckt, though: a G element is a VCCS (voltage-controlled current source), but it is sensing a current I(v1),
which makes it look like it should be a current-controlled source.
Is it a CCCS or a CCVS??

So this is the calling to the subckt:

X_U5         VCC A VCC HIZ CSWIL PARAMS:  IL=3000U

subckt CSWIL (1 2 3 4)
 parameters IL = 800u
CCS (3 4 1 2) cccs gain=1 min=-IL max=IL
ends CSWIL

This should do it. The subckt you had shorted terminals 1 and 2 (through v1), measured this current, clamped it between +/- IL, and output that current.