create-fontset-from-ascii-font is a compiled Lisp function in `fontset.el'.

(create-fontset-from-ascii-font FONT &optional RESOLVED-FONT FONTSET-NAME)

Create a fontset from an ASCII font FONT.

Optional 2nd arg RESOLVED-FONT is a resolved name of FONT.
If omitted, `x-resolve-font-name' is called to get the resolved name.
At this time, if FONT is not available, an error is signaled.

Optional 3rd arg FONTSET-NAME is a string to be used in
`<CHARSET_ENCODING>' fields of a new fontset name. If it is omitted,
an appropriate name is generated automatically.

It returns a name of the created fontset.