Ordering with numbers and text

[SamA74]

I have another ORDER BY question. This is a MySQL database accessed via PHP.
There is a column (class) I want to use for ordering which is varchar type, the values in it are mainly integers, except a few are text strings.
So that the numbers order properly (as if int type) I am currently converting to decimal.
Simplified example:-

"SELECT stuff FROM table WHERE this = :that ORDER BY something, convert(`class`, decimal)"

That works except that the text gets converted to a value of 0 so comes before the numbers.
What I want is for the numbers to sort as integers then the text always comes after the numbers, not before.

[r937]

ORDER BY CASE WHEN 0+class = 0 THEN 'humpty' ELSE 'dumpty' END , 0+class , class

[SamA74]

That appears to be working. Thank you.
I thought it must be something involving CASE but was not sure how to combine that with treating the numbers as integers, not text.