Extract INT From String?

I have a table which has important information stored within a text field as nText. The fields look like this

{B:P:8}
{B:D:18}
{A:P:821}
{E:D:38}
{A:D:9}
{B:D:18}

The integer after the last colon & before the curly brace is the one I need to extract. Is there a way to do this in SQL?

I tried this at first, but the problem is that it's not very tolerant to the varying lengths of the integer.

,RIGHT(LEFT(CAST(bN.Note AS NVARCHAR(50)),6),2)

I use Microsoft SQL 2008