Hello DOJO

We are using a parameter definition to change the lines color of a shape, according to the value of pos_S11 table parameter.
like this:
1003,pos_S11|LineColor;=1,gray;=0,Green
It works fine

But what would be the way to base the LineColor on the value from 2 parameters,  like <A> or <B> ?
In our case, base on position of S15 and S11.