INPUT() and complex numbers?

[DrD]

How can complex numbers be used with INPUT()?

Simple example:

INPUT(zl); // Using zl=50+25i as input value
zo:=50;

RE(zl)=>50, IM(zl)=>25.
(zl-zo)/(zl+zo) => 0.06 +0.24*i

I haven't been able to get complex numbers to work with an INPUT().