Two choices.

Assuming you have a PC sound card you can get a midi breakout cable which plugs into the joystick connector (15 way D) and gives you Midi in and out capability. Depending on the cable you may still be able to use the joystick afterwards! This cable should be available at a decent PC or Music store.

The Triton has a "To Host" interface terminal which will connect to a serial port on the PC. The cable and generic software should be available at a good music store; Korg have a suitable driver on their web site.

The "To Host" cable should be less expensive and works just as well. I don't know the capabilities of the Korg driver but I can tell you that my Yamaha MU80 can be configured as a midi interface when using the "To Host" connector, so you get the midi ports anyhow.

Either way, once the appropriate software and hardware is installed you should be able to configure your PC sequencer to use the new midi device.

If you haven't got a PC sequencer software package yet then personally I like Cakealk but I'm sure you'll get other opinions!