RPM build spec help

[Dan Track]

Hi

I hope someone can help. Basically I want to access an environment
variable and place it in my  macro in my spec file.

If I try to define a macro like the following:

%define oracle_home $ORACLE_HOME

and then try to build it "rpmbuild -ba perl-DBD-Oracle"

I get the following error:
error: line 18: Dependency tokens must begin with alpha-numeric, '_'
or '/': BuildRequires: $ORACLE_HOME/lib/libclntsh.so

On line 18 I have the following:
BuildRequires: %{oracle_home}/lib/libclntsh.so

Any ideas how I can resolve this?

Thanks in advance
Dan