Thank you for answering me. Actually, I took a look at ActionsTest samples, and like always it gives me the good way to code it (but like always, I never think of looking at it).
What I wanted to do was to replace the sprite at its original position after a MoveTo action (not sure if it was clear in my first post). My first idea was to call a callback that will place the sprite at its right position with the help of the data I pass trough the CCArray object (couple of points startPos/endPos). But there was a better solution using CCPlace.
The right code is now (his one is using MoveBy and not MoveTo):
CCPoint originalPosition = CCPoint(100,100);
CCActionInterval* moveBy = CCMoveBy::create(1, CCPointMake(150,0));
CCActionInterval* repeatForeverWrapper = CCRepeatForever::create((CCActionInterval*)CCSequence::create( CCPlace::create(originalPosition)), moveBy, NULL));
Now it should be ok, I just want to add a fadeIn/fadeOut effect at the beginning and at the end of this animation. CCSpawn should do the trick with another CCSequence containing those two effects.