The Perso-Arabian charectars are arranged according to the similarity or shape,unlike the devnaagri charecatrs which are grouped phonetically।The urdu alphabet,It must be remembered is composed of the arabic,persian and hindi letters.
The urdu gutturals kaaf (ک) and gaaf (گ) , pronounced by lifting the root of the tongue at the throat, correspond to क and ग while kha (کھ) and gha (گھ) with aspiration have the same articulation as ख and घ in Devnaagree।
The harsh guttural "Khai" (خ) is pronounced with greater force and roughness and resembles
The soft guttural "ghain" (غ) is articulated well down the throat with a vibration and denoted by ग़
and the deep guttural qaf (ق) denotes क़
The Pharyngeal "ain" (ع) is indicated by by the spiritus asper (ء) followed by a wovel in devnaagri and sometimes is used for अ
There is a slightly pharyngeal (ۂ) which has its corresponding to ह in devnaagri ।
Now, There is another ( حـ) which denotes ह with a slight dot below it-The same way one would put below qaf as क़ and ghain as ग़ .unfortunately devnaagri doesn't have a letter defined and therefore it can not be shown.