Shader with adjustable render queue

Hi,

I'm trying to build a shader that has a text field for a custom render queue tag. I'd like this to be a number I can specify so that I don't have to create a new copy of my shader every time I want to adjust the queue.

I've got the text field working, and I know where the number needs to go. I'm just not sure how to tell the shader to use the number, and now I'm wondering if this is a limitation of this in Unity.

I guess my question is, can I use a variable in my shader to define the render queue, and if so, how would I get that to work?

 Shader "Render Queue" {
     Properties {
         _Color ("Color Tint", Color) = (1,1,1,1)    
         _MainTex ("Base (RGB) Alpha (A)", 2D) = "white"
         _Depth ("Render Depth", Float) = 0  //This is what I'd like to add
     }
 
     Category {
         Lighting Off
         ZWrite Off
         Cull back
         Blend SrcAlpha OneMinusSrcAlpha
 
         SubShader {
             
             Tags {"Queue" = [_Depth]}  //This line doesn't work, but it gives an idea of what I'm trying to do
             
             Pass {
                 SetTexture [_MainTex] {
                     ConstantColor [_Color]
                     Combine Texture * constant
                 }
             }
         }
     }
 }