Just the "DD"?
It would take less time to simply make a suitable Dalet from scratch!
Or maybe even just take the "L" and rotate it 180...

hhp

Sorry. I should have added more details. I only need it to match the "DD" because in my design it would only say DD in Frankfurter.

It would have read, "DD אני "

That was what I originally had in mind and may switch back to that.
Now instead of writing out the "DD" in english letters I plan to use the Hebrew letters for D. I guess, I would still need a font that would match Frankfurter but now I think theres more freedom since the "DD" wont be present in the design.

Now it will read "אני דד "

Which one? There are indeed many matches? See www.gohebrew.com