Is it permissible for a colleague to stipulate to the one who gives him a daily ride that he must give daily charity with the intention that half of the donated amount is for him and the other half is for him?

If the fare is known and the car owner wishes to authorize you to donate it on his behalf, this is not permissible according to the Shafi'i school of thought. This is because it is not permissible for a person to be both the recipient and the giver at the same time, except in cases specifically exempted by jurists, due to the unity of the recipient and the giver. You can agree with your colleague on a known fare that he receives from you, and then he has the choice to spend it, donate it, or authorize you to donate it. He should also transport you for free, seeking reward and recompense from Allah, as this is a noble deed, an act of gratitude for Allah's blessings, and a facilitation for you. The prophetic traditions have encouraged assisting one's companion, such as the hadith narrated by Abu Sa'id al-Khudri, recorded by Muslim: "Whoever has a surplus mount should give it to one who has no mount, and whoever has surplus provisions should give them to one who has no provisions." Imam al-Nawawi mentioned that this hadith encourages charity, generosity, solidarity, kindness to companions, and attending to their needs.