What exactly are you trying to do?
Most LIPO battery chargers for more than one cell need some kind of balancing capability
to ensure that each cells voltage remains the same as the battery is charged.
This involves not only monitoring the individual cell voltage, but also controlling the current thru each cell.
Whilst this may sound easy to do its anything but easy, due to the multiple voltages and currents that have to be individually controlled.
As a result , there are dedicated LIPO battery balancing ICs, which do all the hard work for you.
Something like this
Texas Instruments and Maxim also make LIPO battery balancers.