Curve text on existing circle

For an application I am building I have drawn 2 circles. One a bit bigger than the other. I want to curve text between those lines, for a circular menu I am building.

I read most stuff about curving a text that you have to split up your text in characters and draw each character on it's own with the right angle in mind (by rotating the context you are drawing on).

I just can't wrap my head around on how to get the right angles and positions for my characters.

I included a screenshot on what the menu, at the moment, look like. Only the texts I added by are loaded from an image in an UIImageView.

I hope someone can get me some starting points on how I can draw the text in the white circle, at certain points.

EDIT: Ok, I am currently at this point:

I accomplish by using the following code:

- (UIImage*) createMenuRingWithFrame:(CGRect)frame
{
    CGRect imageSize = CGRectMake(0,0,300,300);
    float perSectionDegrees = 360 / [sections count];
    float totalRotation = 90;
    char* fontName = (char*)[self.menuItemsFont.fontName cStringUsingEncoding:NSASCIIStringEncoding];

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, imageSize.size.width, imageSize.size.height, 8, 4 * imageSize.size.width, colorSpace, kCGImageAlphaPremultipliedFirst);

    CGContextSetTextMatrix(context, CGAffineTransformIdentity);
    CGContextSelectFont(context, fontName, 18, kCGEncodingMacRoman);

    CGContextSetRGBFillColor(context, 0, 0, 0, 1);

    CGPoint centerPoint = CGPointMake(imageSize.size.width / 2, imageSize.size.height / 2);
    double radius = (frame.size.width / 2);

    CGContextStrokeEllipseInRect(context, CGRectMake(centerPoint.x - (frame.size.width / 2), centerPoint.y - (frame.size.height / 2), frame.size.width