To write arabic unicode script in MsOffice using shortcut, type fdfa then press alt+x, it will convert into its respective unicode

To write in HTML, type ﷺ  it will render it as respective unicode.

It may be require to increase the font to make it more readable

Below are some examples

fdfa Alt+x صلى الله عليه وسلم

Fdf2 Alt+x الله

Fdf3 Alt+x اكبر

Fdf4 Alt+x محمد

Fdf5 Alt+x صلعم

Fdf6 Alt+x رسول

Fdf7 Alt+x عليه

Fdf8 Alt+x وسلم

Fdf9 Alt+x صلى 

Below URL to list all unicodes

www.unicode.org/charts/PDF/Unicode-3.1/U31-FB50.pdf