Calculated column to display custom form field label and value

We have an "Issue Complexity" custom form field with labels and values as follows: Low Complexity = 5, Medium Complexity = 10, High Complexity = 15. I would like to have a report column that displays the label and value together, "Low Complexity - 5", etc. but I can't figure out how to get the label to display. Below, {DE:Issue Complexity} displays the value, but what would I need to put in for the label to show up? I've tried {name} and {label}, neither worked.

displayname=Issue Complexity

textmode=true

valueexpression=CONCAT({DE:Issue Complexity}.?????," - ",{DE:Issue Complexity})

valueformat=HTML

I was able to do a workaround with the below, but I would like to get the above to work since it's so much simpler.

column.8.displayname=Issue Complexity & Score

column.8.linkedname=direct

column.8.namekey=Issue Complexity

column.8.querysort=DE:Issue Complexity

column.8.sharecol=true

column.8.textmode=true

column.8.valuefield=Issue Complexity

column.8.valueformat=customDataLabelsAsString

column.9.sharecol=true

column.9.textmode=true

column.9.value=<br>

column.9.valueformat=HTML

column.10.displayname=Issue Complexity Value

column.10.linkedname=direct

column.10.namekey=Issue Complexity

column.10.querysort=DE:Issue Complexity

column.10.textmode=true

column.10.valueexpression={DE:Issue Complexity}

column.10.valueformat=