[NEST Users] LIF neuron with both current based and conductance based synapses

Dear all, I am trying to implement a network consisting of LIF neurons with mixed current based and conductance based synaptic connections. Eg. one LIF neuron which gets two inputs from which one is treated as current input and the other as conductance input. That means, how to treat the input should be encoded in the synapse and not in the type of the postsynaptic neuron. Is such a neuron model already implemented or is there a way to implement this? Thanks for your help. Best, Hartmut