在Cocos2d-x的TestCpp工程中有这样一个效果，来自LabelTest

效果图：

控制指定位置上的字符执行一个动作。

通过Label的getChildByTag(idx)可能获取到指定位置上的字符，索引0表示第1个字符，返回的字符是一个CCSprite，这样就可以控制指定位置的字符执行的动作了。

实现代码：

    // Upper Label
    CCLabelBMFont *label = CCLabelBMFont::create("Bitmap Font Atlas","fonts/bitmapFontTest.fnt");
    addChild(label);
    
    CCSize s = CCDirector::sharedDirector()->getWinSize();
    
    label->setPosition( ccp(s.width/2,s.height/2) );
    label->setAnchorPoint( ccp(0.5f,0.5f) );
    
    
    CCSprite* BChar = (CCSprite*) label->getChildByTag(0);
    CCSprite* FChar = (CCSprite*) label->getChildByTag(7);
    CCSprite* AChar = (CCSprite*) label->getChildByTag(12);
    
    
    CCActionInterval* rotate = CCRotateBy::create(2,360);
    CCAction* rot_4ever = CCRepeatForever::create(rotate);
    
    CCActionInterval* scale = CCScaleBy::create(2,1.5f);
    CCActionInterval* scale_back = scale->reverse();
    CCSequence* scale_seq = CCSequence::create(scale,scale_back,NULL);
    CCAction* scale_4ever = CCRepeatForever::create(scale_seq);
    
    CCActionInterval* jump = CCJumpBy::create(0.5f,CCPointZero,60,1);
    CCAction* jump_4ever = CCRepeatForever::create(jump);
    
    CCActionInterval* fade_out = CCFadeOut::create(1);
    CCActionInterval* fade_in = CCFadeIn::create(1);
    CCSequence* seq = CCSequence::create(fade_out,fade_in,NULL);
    CCAction* fade_4ever = CCRepeatForever::create(seq);
    
    BChar->runAction(rot_4ever);
    BChar->runAction(scale_4ever);
    FChar->runAction(jump_4ever);
    AChar->runAction(fade_4ever);