To pass parameters to a function in the class ICSSoft.STORMNET.Web.Tools.AdvLimitUtils there is a method:

/// <summary> 
/// Substitute a specific value instead of function parameters. 
/// </summary> 
/// <param name="function">the function that will replace the parameters.</param> 
/// <param name="paramValues">the Reference values of parameters (parameter name - value).</param> 
/// <returns>the Function in which all parameters replaced by the appropriate values.</returns> 
public static Function SubstituteParameters(Function function, IDictionary<string, object> paramValues)

Example

ExternalLangDef externalLangDef = ExternalLangDef.LanguageDef;
 
 // The bounding function. 
 ICSSoft.STORMNET.FunctionalLanguage.Function limitFunction = externalLangDef.GetFunction(
   externalLangDef.funcEQ,
   new ParameterDef(Date, externalLangDef.DateTimeType, false, "")); 

 // The function with the substituted value. 
 limitFunction = AdvLimitUtils.SubstituteParameters(
    limitFunction,
    new Dictionary<string, object>() { {Date, DateTime.Now} });

Additionally ##

Substitution of parameter values in the bounding function (Win)