Because you're looking for a soundcard with MIDI ports, it's obvious then that you're after MIDI music although you might still want to try audio recording...anyways:
For a good quality soundcard/audiocard (with MIDI In/Out ports and audio LINE-IN ports as well), check this out: M-AUDIO 2496
I use the M-audio 2496 audiocard in my PC in addition to my old Creative Soundblaster Live 5.1 Platinum soundcard: Creative Soundblaster Live! 5.1 Platinum review
There are a lot of MIDI-audio sequencing softwares available...some/few are free and
most[/b] are of course sold in music stores or on-line.
For starters...if you want a "basic" MIDI software package that contains a "Getting-started" with MIDI manual (that can guide you in the basic functions and how to arrange/Record in MIDI) for use with the accompanying software, try this link: USB-MIDI studio kit
NOTE: This is just one of several basic MIDI sequencing softwares available. I leave the other forum members to give out better suggestions. Personally, I started out with Voyetra's MIDI Orchestrator software several years ago, then shifted to Cakewalk Pro Audio which I used for a couple of years (upgrading only twice which lead me to Cakewalk Pro Audio version 8) until I finally shifted to Cakewalk Sonar 6 P.E. (producer edition).
By the way, you can still connect your CP-33 to your PC/laptop even if you don't have a soundcard if you can find a MIDI-to-USB converter (like the one included in the Voyetra software I linked above) or you can check this out: M-Audio Uno MIDI to USB connector
As a side note, however, although keyboard and digital piano manufacturers provide USB-MIDI drivers for their products, you might still encounter "compatibility" problems between the provided USB-MIDI driver and the OS that you're using. In line with this, I'm still using Windows XP and I like it that way in so far as it keeps my soundcard/audiocard hardware, sequencing softwares running without problems. Personally, I wouldn't exchange this "problem-free" setup that I currently have for whatever "eye-candy" Vista might offer to the PC user. I'm more interested in the process of creating/arranging music and in this regard Windows XP has proven to be a "stable" OS for this purpose. I'm mentioning these things because it's possible that you might encounter problems between some USB-MIDI drivers and softwares and/or OS...just so you'd be aware too.
Good luck and happy learning.