I figured it out. So I'll reply to my own message, since nobody else has. If anyone else has had the same problem, it's actually really easy: go to Preferences, click the Control tab, click Add. When it prompts you to press any key combo, do it WHILE that dialogue window is open (for some reason I couldn't figure that out). You then choose what function you want to assign to that key combo. Try not to use a combo you already use often in another app (Word, for example), such as Command-I for Italics, as the Scribe function will override it!
Best,
DoctorJBA