So I am trying to find business seat from CHC to IAD. Of course, there is no availability. However, there were plenty of business award seat between CHC-IST, and IST-IAD.

If I find flights for both segments and reasonable connect time between them, can I call in to book it? Are there any restrictions stitching them together?

Assuming it's a round trip without stopover, is there restriction of #s of flights? Thanks in advance