the "multi" option will automatically put longer text labels on two lines on a dialog button, is there any way to 'force' a line break, or to manually insert one?

"line 1 $cr line 2" doesn't work for a button label. the button is 60 x 30, sometimes I'll have

title
line 2

sometimes I'll have

longertitle
line 2

using 'multi', wraps "longertitle" on the button, so it becomes

longerti
tle
line 2