The compatibility of an Arabic font with a specific English font

Hi all

Suppose I designed an Arabic font called X
How can I make X font compatible with a specific English font when typing in Arabic and English in one sentence?

for example

I write in my font called X in Arabic in a sentence in ( Microsoft word or pages on Mac ) when I convert the writing to English I want the English written in ( Arial font ) not any other English font

How can that be done ?
@mekkablue @GeorgSeifert