Stay longer than 180 days? Any way?

I am of German nationality and stay here in Taiwan for some research. I am holding a visitor visa that was issued for 60days and I already extended it for 60 more days. The second extension will be next month and hopefully last until end of July. Then the 180days are gone.

My problem right now is that I applied for a chinese language claas which starts end of June.
I have admisson letter of university already.
Is there a chance to change my visitor visa to something else so that I don