I don't know of an easy way to do this with aptitude. Running
apt-get install ndiswrapper-utils-1.9 --print-uris on the target system will give you a list of package URLs, which you could download directly (if you are proficient with bash, you could probably write a script to do it automatically in a few minutes).
If you want to do it manually, package files are on packages.debian.org - here is ndiswrapper-utils for debian stable, which depends on all the other ndiswrapper packages (make sure you download the i386 packages).
You will need to download the dependencies too (ndiswrapper-common, ndiswrapper-dkms, and ndiswrapper-source) which are needed to build the kernel module. (also, you will need all the packages necessary to build a kernel module, like dkms, kernel-package and module-assistant, but you may already have these on your system). The website will tell you which dependencies are needed for which packages.
Then, install them in reverse order (dependencies first, then the package that depends on them). You can use the graphical package manager or
# dpkg -i <package file> to install them. If you're missing a dependency, it will tell you and you will have to install that first.