Is it possible to pass a parameter from a technique to a vertex/pîxel shader?

Question

I modified some shaders in unity and I'm trying to modify one in Cryengine.

Can I send a parameter when I call a vertex/geometry/pixel shader in the technique?

Something like

//--------
MytVertexShader bla bla ;
MyGeometryShader bla bla ;
MyPixelShader bla bla ;
//-------
technique
{
    pass p0
    {
        vertex shader = MyVertexShader (myParameter1) ;
        geometry shader = MyGeometryShader (myParameter2); 
        pixel shader = MyPixelShader (myParameter3)
    }
    pass p1
    {
        vertex shader = MyVertexShader (myParameter4) ;
        geometry shader = MyGeometryShader (myParameter5); 
        pixel shader = MyPixelShader (myParameter6)
    }
}
//--------

The goal is to have only one of each shader code with optional variations based on MyParameter.