I really like the tune option and @paulvdh 's idea very much, however it won’t work correctly in your specific circuit. You’re using all three terminals of the potentiometer, i.e. ratio-metric, and his approach will only work if you were only using two terminals (like a rheostat). I tried my best to incorporate a way to use the tune functionality, but it’s too limited of a feature to be used practically for a full potentiometer. You can somewhat pull it off with two resistors, but then you have to manually adjust two sliders and keep track of the total resistance in your head while doing it.
Therefore, I agree that @holger 's approach is the best way to handle this, especially since it preserves the schematic for actual circuit layout and construction. Here is an attached sample project that shows on the left how to do it using two discrete resistors and .param statements. Then on the right, the idea is finished by putting the two resistors in a subcircuit and then adjusting the on-schematic text for “value” and “ratio”. If you simulate, you can see that both outputs are the same.
pot_test.zip (6.6 KB)
The default parameters should be in the text file (see the included RPOT_subckt.lib), and then they can be overridden in the schematic via that purple text box in my example that says: RPOT value=10k ratio=0.4