Add a tap gesture to a part of a UILabel

I think, the best way is adding the UIGestureRecognizer to your UILabel and validate the frame that you would like.

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];
[_yourLabel addGestureRecognizer:singleTap];

- (void)handleTap:(UITapGestureRecognizer *)tapRecognizer
{
    CGPoint touchPoint = [tapRecognizer locationInView: _yourLabel];

    //Modify the validFrame that you would like to enable the touch
    //or get the frame from _yourLabel using the NSMutableAttributedString, if possible
    CGRect validFrame = CGRectMake(0, 0, 300, 44);

    if(YES == CGRectContainsPoint(validFrame, touchPoint)
     {
        //Handle here.
     }
}