+1 for sampling the sound. There are a lot of products that will generate sample sets from keyboards. Sample Robot has this functionality, as does Extreme Sample Converter. ESC is the less expensive option, going for EUR 39.
Of course, I would recommend converting these into sfz format. There are a lot of instruments which are free or that you already have that will play these.
On the other hand, if you think that Dim Pro patch is close enough it shouldn't be hard to fix. I won't be on my DAW for a while, but...
1. Each DP patch has up to four elements. Try turning them off one at a time to narrow where the oscillation is coming from.
2. Once you have figured out which element is generating the oscillation, you can look at the edit screen for each element. There should be tabs for controlling the PITCH, CUT, RESO, PAN, AMP. Under each of these tabs, there is a section on the left for LFO. There is a Status underneath this. Turn it to Off. Repeat this for each tab.
3. Similarly for each tab there is an envelope graph. You can turn this off by clicking the Status control, which is on the right under EG to Off. Or you can click on points on the graph to modify the envelopes.
A third thing you can try is Zen by Big Tick. I haven't tried it yet, but it allows you search for sounds amongst all of the VST plugins you have.
http://www.bigtickaudio.com/zen/about-zen