Sure! Here's an example with a custom search syntax. Just pop that in an SDK script in workflow and change your parameters. This example sets a token value created in the workflow called "SearchDocumentCount" to return something meaningful.

namespace WorkflowActivity.Scripting.SearchStats
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Data.SqlClient;
    using System.Text;
    using Laserfiche.RepositoryAccess;

    /// <summary>
    /// Provides one or more methods that can be run when the workflow scripting activity is performed.
    /// </summary>
    public class Script1 : RAScriptClass102
    {
        /// <summary>
        /// This method is run when the activity is performed.
        /// </summary>
        protected override void Execute()
        {
            // Write your code here. The BoundEntryInfo property will access the entry, RASession will get the Repository Access session
            Search search = new Search(RASession,"{LF:AssociatedPages=\"YES\"} & ({LF:OCR=\"none\"} | {LF:OCR=\"some\"}) -({[Fuel]:[Type-Fuel Transaction]=\"BOL\"})");
            search.Run();
            SearchStatistics stats = search.GetSummaryStats();
            int searchdocumentcount = stats.DocumentCount;
            int pagecount = stats.PageCount;
            long eletronicfilesize = stats.ElectronicFileSize;
            int foldercount = stats.FolderCount;
            long imagefilesize = stats.ImageFileSize;
            long textfilesize = stats.TextFileSize;
            SetTokenValue("SearchDocumentCount",searchdocumentcount);
        }
    }
}