The best thing to do is go back to the theory books, As Kral has pointed out, this is not a device to be used in a linear application, it is intended as a ground side power switch. The 'COM' pin is the common junction of internal diodes, intended to clamp the 'kick back' from switching inductive loads off. It will do nothing at all if you attempt to use the IC in a linear mode but if you connect it to less than your supply voltage it will cause unexpected output voltages. The 'GND' pin is the common emitter connection of all the internal transistors and bias networks, you can not use it as an output, at least with predictable results. Suggesting you inject 25mA into the base (input) pin is also ridiculous as it would need more than 68V at the pin to make that much current flow, it is voltage driven, not current driven and the voltage to reach saturation is less than 5V.
If you are really looking for a current amplifier, consider just a single bipolar transistor, you are only asking for a gain of 4 so it isn't complicated.
Brian.