DW CS5 rtl text snippits within ltr pages

Question

DW CS5 on MacOS 10.7.x
I sometimes need to embed short snippets of right-to-left text in pages that are predominently left-to-right.
Editing around these insertions is often very difficult.  Design View and Code View fall out of synch.   Once the snippets are inserted, successful adjustments often depend on placing the editing cursor at the opposite end of the text and editing there.  Yeah,  it is really difficult confusing editing text that isn't visible at the cursor.
Since most of the mixed material comes to me in word-processing document form, I've tried inserting
     <span DIR="RTL"> ... </span>
around each snippet and
    <span DIR="LTR"> ... </span>
around everything in the original .DOC or .rtf, etc., then copying-and-pasting from that dic ti  to Code View.  This seems to help.
Suggestions for best results?
TIA

Answer 1

Ken Binney:
Thanks for your response.    I DID ask for a workaround!  (A specific reply further down.)
I've continued to search and found some additional relevant material:
1) This page contains some well-thought-out  examples of inserting RTL snippets in LTR Latin English text.  See the 2 x 2  table about 1/3 of the way down,  just below the text, "This example shows how browsers that support bidirectional text behave with different DIR attribute settings."
Note the reversals (character and right- versus left-alignment) in the right column due to using dir="LTR" and dir="RTL" directives, which are shown in the left column.    What I see  makes intuitive sense to me.  It looks the same in recent versions of Firefox, Safari, and Chrome.  Which I guess means that these modern browsers all support bidirectional text.
I  saved this page into a local file and opened it in DW.  Hmmm,  the reversals do NOT occur.  The two sentences in each of the right-hand boxes are identical.   Which, to me, implies: 
DW CS5 Design View does NOT support bidirectional text. 
(A possibly equivalent statement:  DW CS5 ignores "dir=" directives.)
2) I should have mentioned from the start that I'm using Unicode throughout.    I think MacOS uses Unicode, and that's why RTL snippets inserted in LTR Latin English text work correctly in the Mac apps I checked.   I'm guessing the underlying mechanism is described here.
Whew!  That's really a lot of industrial-strength tekkie material, but for this discussion, I think it boils down to this:  Unicode-capable apps insert and detect non-printable "Bidi Controls" indicating text direction.   I can maintain a Hebrew snippet in (say) LibreOffice: it is fully Unicode-capable.
Is DW CS5 fully Unicode-capable?
3) I found this article, which specifically addresses  your workaround.   Again, some high-powered tekkie material, but the relevant bottom line seems clear enough:  don't  use CSS to control text directionality, essentially because that's too far downstream.
4) The definitive document on this issue might be this one from W3C.
Much more dense tekkie material, unusually well-explained, but:  My head is spinning!   For the moment I'm going to concentrate on one section, The "missing space' phenomenon", here.
I saved the markup for the second example (circle-arrow link at right), which I presume is completely valid.  When I tried to edit in and around the Hebrew text in DW CS5, I observed the same problems:  putting the insertion point here, resulted in editing there.
Bottom line:  The evidence I've found so far is that DW CS5 does not have full bidirectional text support and/or does not fully support Unicode.   If so, I think that this is more than sufficient to explain the poor editing results I'm seeing.
Here's a desperate hope:   The problems I'm observing can be fixed by flipping a hidden DW switch to activate full bidirectional text/Unicode operation.
Am I interpreting the evidence correctly?   Please feel free to correct me, prove me wrong, and suggest alternatives.  Even better, please --anyone-- suggest a simple way I can get back to my  actual work,  which requires embedding RTF snippets in LTR text flows, with normal editing capabilities.
TIA