kathyP: …it is Inherit because the document is right to left.
I may be of limited help here, never having needed to work with RTL documents.
I would have expected FM to have some way of dealing with mixed-direction text, but some searching doesn't turn up anything except for structured documents.
Various hacks come to mind, like ◊ run-in ¶formats with LTR set, ◊ variables for the LTR strings, or ◊ using some non-standard mark-up for the hyphens, so that the algorithm doesn't mess with them. Character Format doesn't have a field for direction, alas.
I would be pleasantly surprised if FM honored any of these Unicode control characters: U+202A LEFT-TO-RIGHT EMBEDDING U+202B RIGHT-TO-LEFT EMBEDDING U+202C POP DIRECTIONAL FORMATTING U+202D LEFT-TO-RIGHT OVERRIDE U+202E RIGHT-TO-LEFT OVERRIDE but I haven't tested any.