My suggestion would be install apt-file, either using aptitude or apt-get or synaptic if you prefer.
Then as root:
apt-file update
Once that is done, you can do apt-file search libpangoxft and see what package, if any, in Debian contains it. Then install that package. Or create a dummy package that depends on it and install that, so the library will get removed again if you don't need it later and not clutter your system up.
If the package you need turns out to be the one you already tried, we will need to know the exact errors you are getting to help further.
Mark