You can use the SQL script provided in Locating File in Laserfiche based on File Path in Volume

Or here is a slightly easier query to get docid from volume file.  Just edit the first 3 SET values and then execute.

DECLARE @IsImage bit,
        @FileName varchar(10),
		@VolName nvarchar(63)

-- Edit the below 3 SET values
-- @IsImage Options
--  0 = No(Electronic Document), 1 = Yes(TIFF Image)
SET @IsImage = 0
-- copy the whole file name without extention
SET @FileName = '0000029B'
-- Copy the folder name of the folder that contains the 00 and e00 folders
Set @VolName = N'DEFAULT000001'

-- Do Not Edit Below This Point
DECLARE @iFileName int,
		@hexstr nvarchar(10),
		@hex char(1),
		@i int,
		@place bigint,
		@a bigint
    -- Get integer value from File Name
    SET @hexstr = '0x' + @FileName
    SET @i = LEN(@hexstr) 
	SET @place = CONVERT(bigint,1)
    SET @a = CONVERT(bigint, 0)

    WHILE (@i > 0 AND (SUBSTRING(@hexstr, @i, 1) like '[0-9A-Fa-f]')) 
     BEGIN 
        SET @hex = SUBSTRING(@hexstr, @i, 1) 
        SET @a = @a + 
    CONVERT(bigint, CASE WHEN @hex LIKE '[0-9]' 
         THEN CAST(@hex as int) 
         ELSE CAST(ASCII(UPPER(@hex))-55 AS int) END * @place)
        SET @place = @place * CONVERT(bigint,16)
        SET @i = @i - 1
    
     END 
SET @iFileName = CONVERT(int, @a)


If (@IsImage = 1)
  BEGIN
    SELECT [dbo].[doc].[tocid] AS [EntryID]
    FROM [dbo].[doc]
    INNER JOIN [dbo].[toc]
    ON [dbo].[doc].[tocid] = [dbo].[toc].[tocid]
    INNER JOIN [dbo].[vol]
    ON [dbo].[toc].[vol_id] = [dbo].[vol].[vol_id]
    WHERE [dbo].[vol].[vol_name] = @VolName AND [dbo].[doc].[storeid] = @iFileName
  End
Else
  Begin
    SELECT [dbo].[toc].[tocid] AS [EntryID]
    FROM [dbo].[toc]
    INNER JOIN [dbo].[vol]
    ON [dbo].[toc].[vol_id] = [dbo].[vol].[vol_id]
    WHERE [dbo].[toc].[edoc_storeid] = @iFileName AND [dbo].[vol].[vol_name] = @VolName
  End