How to update a constant programmatically

I have a list of constants and want to update them all one at a time. I'm using the smart service to update constants but it seems to require me to manually specify the constant to update. 

I tried doing the following.

In my form I have the data subset in my form which I use to set the value

 
  local!scoreData: todatasubset(
    {
      {parameter:"Change Management Complexity Simple", value: cons!BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_SIMPLE_VALUE, consName: " BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_SIMPLE_VALUE"}, 
      {parameter:"Change Management Complexity Moderate", value: cons!BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_MODERATE_VALUE, consName: "BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_MODERATE_VALUE"}, 
      {parameter:"Change Management Complexity High", value: cons!BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_HIGH_VALUE, consName: "BPMT_VAL_NEW_PROCESS_EFFECTIVENESS_HIGH_VALUE"},   
      {parameter:"Effectiveness Simple", value: cons!BPMT_VAL_CHANGE_MGMT_COMPLEXITY_SIMPLE_VALUE, consName: "BPMT_VAL_CHANGE_MGMT_COMPLEXITY_SIMPLE_VALUE"}, 
      {parameter:"Effectiveness Moderate", value: cons!BPMT_VAL_CHANGE_MGMT_COMPLEXITY_MODERATE_VALUE, consName: "BPMT_VAL_CHANGE_MGMT_COMPLEXITY_MODERATE_VALUE"}, 
      {parameter:"Effectiveness High", value: cons!BPMT_VAL_CHANGE_MGMT_COMPLEXITY_HIGH_VALUE, consName: "BPMT_VAL_CHANGE_MGMT_COMPLEXITY_HIGH_VALUE"}, 
      {parameter:"Cost reduction Threshold 1", value: cons!BPMT_VAL_250K, consName: "BPMT_VAL_250K"},
      {parameter:"Cost reduction Threshold 2", value: cons!BPMT_VAL_1M, consName: "BPMT_VAL_1M"}
    }
  ),

I created a loop in the process model to grab one item at a time and pass it into the smart service node in the following way.

constant:

getconstantorruleuuidbyname(index(index(pv!scoreData.data, "consName", null),pv!counter,null))

value:

=index(index(pv!scoreData.data, "value", null),pv!counter,null)

If I run this I get the following error: "The constant specified is invalid or does not exist. Constant ID: -2,147,483,647". It doesn't like that I'm passing the uuid instead of an actual constant.

Is there a way to get around this?