.
While it is true that BiaB does not have a feature called "Orchestral Strings," it does provide a number of ways to create string parts. For example, BiaB writes string parts for many of the included styles.

Have you tried all the ways that BiaB can create string parts?
In what way are they not what you want?

Please explain what you have tried, and what you want to do.

Flatfoot sez: Call me when 'Talent-in-a-Box' is ready to ship! -- [8{>

Got some tunes on You Tube:
http://www.youtube.com/user/flatfoot50
.
My BiaB lesson site:
http://jdwolfe0.wixsite.com/learnbiab