Wow you are still running Etch? Security support for Etch ended back in February.
Only way you are going to get 0.96 is by building it from source or updating to the current Stable. And even using Lenny you would have to get clamav from volatile.
http://packages.debian.org/search?ke...ll§ion=all
lenny-volatile (utils): anti-virus utility for Unix - command-line interface
0.96+dfsg-4~volatile1 [volatile]: alpha amd64 hppa i386 ia64 mips mipsel powerpc s390 sparc
0.95.3+dfsg-1~volatile1 [volatile]: armel