  For the Borel part of a quantized enveloping algebra we classify all right
coideal subalgebras for which the intersection with the coradical is a Hopf
algebra. The result is expressed in terms of characters of the subalgebras
$U^+[w]$ of the quantized enveloping algebra, introduced by de Concini, Kac,
and Procesi for any Weyl group element $w$. We explicitly determine all
characters of $U^+[w]$ building on recent work by Yakimov on prime ideals of
$U^+[w]$ which are invariant under a torus action.
  Key words: Quantum groups, coideal subalgebras
