Templates/ExpressionDeploy.Params.json

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
      "paramUsingSimpleExpression": {
        "value": "$pwsh[$storageNameFromPS]"
      },
      "paramUsingcomplexEvaluator": {
        "value": "$pwsh[{((Get-AzStorageAccount)[0]).StorageAccountName}]"
      },
      "paramUsingFuncEvaluator": {
          "value": "$pwsh[{(Get-SomeData -testParam '$myVar')}]"
      }
    }
  }