Using {dist} when I only have pre-compiled binaries?

[Matt Harrington]

>From this document, it sounds like {dist} is set by "make tag" or "make build":

https://fedoraproject.org/wiki/Packaging:DistTag

CVS also appears to be involved somehow.

I have precompiled binaries for EL5 that I'd like to package up.
These binaries are different from ones for other distributions.  How
can I set {dist} so the resulting RPM is marked for EL5 only?

Matt