using uCalcSoftware; var uc = new uCalc(); var t = new uCalc.Transformer(); string text = "Replace config, but not the one inside [RAW]this config is raw[/RAW]."; // Create a token set for the raw block that only tokenizes single characters. var rawTransformer = new uCalc.Transformer(); var rawTokens = rawTransformer.Tokens; rawTokens.Clear(); rawTokens.Add("."); // Match any single character // Switch to rawTokens when [RAW] is found, and switch back at [/RAW]. t.Tokens.ContextSwitch(rawTokens, """ \[RAW\] """, """ \[/RAW\] """); t.FromTo("config", "SETTING"); Console.WriteLine(t.Transform(text));