[NEST Users] Control over the synaptic weight and synaptic decay time

Dear all, I hope you are in staying safe. I'm working on a balanced network consisting of "iaf_cond_exp" neurone model. I want to have the control over these parameters at the same time: - increasing the synaptic decay time. - reducing the synaptic weight. The goal is to make the area under the synaptic current, constant. So that we know that the only parameter that is affecting on the network, is synaptic delay. I wonder if you know of any furmula in mathematics or any algorithm, that can help me, making this process automatic. And keeping the area under the curve, a constant value. Best wishes, Nosratullah