[VS2005] Data Structures

[Jumpercables]

I am having a problem trying to keep track of some Excel Files and Sheet names.
These excel files and sheets are created dynamically, when a user clicks some buttons is creates the excel file and the sheet. I have been trying to use an arraylist but for some reason it is loosing files. Is there a better structure I can use that can relate File to Sheet and Sheet to File.

I have thought about a Hashtable for each excel file be the key (since they will always be unique) and value as the sheet name but I need to file name as well.

Here is the code I am using this far...

cQueueExcelFiles and cSheets are both arraylist.

///<summary>
        /// Gets the next excel file in the queue, returns null if nothing left in queue.
        ///</summary>
        public string XlNextFile
        {
            get
            {
                string next = null;
 
                try
                {
                    next = (String)cQueueExcelFile[this.cQueueExcelFile.Count - 1];
                    cQueueExcelFile.Remove(next);
                }
                catch (ArgumentOutOfRangeException)
                {
                    next = null;
                }
                return next;
            }
        }
 
        ///<summary>
        /// Returns the next excel sheet name.
        ///</summary>
        private string XlNextSheet
        {
            get
            {
                string next = null;
                try
                {
                    next = (String)this.cSheets[this.cSheets.Count - 1];
                    cSheets.Remove(next);
                }
                catch (ArgumentOutOfRangeException)
                {
                    next = null;
                }
                return next;
            }
        }
 
///<summary>
        /// Sets the Excel Files waiting to be processed in a Queue.
        ///</summary>
        public string XlQueueFile
        {
            set
            {
 
                if (this.cQueueExcelFile == null)
                {
                    cQueueExcelFile = new ArrayList();
                }
                this.cQueueExcelFile.Add(value.ToString());
            }
 
        }
        #endregion