Hello jecz and thanks for your interest ....I have been researching and found in a catalogue
https://www.tesorillo.com/oca/islam/islam.htm a coin that ,if you compare letters and simbols ( ?) is almost equal to the one that I posted ....and correspond to a DIRHAM with a hole ( Dirham agujereado ) Hixem ( Hixam ) II silver 22 mm , 3,25 grams ...( There is a diference with the one in this post that is 23-24 mm and 3.95 grs ) I hope ,as you hope , that somebody, that really can read the coin , will give us more information .Best .