# PDF Modification Module (pdfMod.bas)

## Overview
This VBA module provides functionality for manipulating PDF files directly within Excel. It includes capabilities for merging PDFs, extracting pages, and handling PDF-related operations.

## Functions and Subroutines

### MergePDFs
Combines multiple PDF files into a single output PDF.


Public Sub MergePDFs(inputFiles As Collection, outputPath As String)


#### Parameters
- `inputFiles`: Collection of file paths to input PDFs
- `outputPath`: Destination path for merged PDF file

### ExtractPages
Extracts specific pages from a PDF file.


Public Sub ExtractPages(inputPath As String, outputPath As String, startPage As Long, endPage As Long)


#### Parameters
- `inputPath`: Source PDF file path
- `outputPath`: Destination path for extracted pages
- `startPage`: First page to extract
- `endPage`: Last page to extract

### AddWatermark
Adds a watermark to each page of a PDF.


Public Sub AddWatermark(inputPath As String, outputPath As String, watermarkText As String)


#### Parameters
- `inputPath`: Source PDF file path
- `outputPath`: Destination path for watermarked PDF
- `watermarkText`: Text to use as watermark

## Dependencies
- Requires Adobe Acrobat installation
- Uses Microsoft Scripting Runtime for file system operations

## Error Handling
- Includes comprehensive error handling for file operations
- Validates PDF file existence and accessibility
- Checks for valid page ranges in extraction operations

## Usage Examples

' Merge PDFs Example
Dim pdfs As New Collection
pdfs.Add "C:\path\to\first.pdf"
pdfs.Add "C:\path\to\second.pdf"
MergePDFs pdfs, "C:\path\to\output.pdf"

' Extract Pages Example
ExtractPages "C:\input.pdf", "C:\output.pdf", 1, 5

' Add Watermark Example
AddWatermark "C:\input.pdf", "C:\output.pdf", "CONFIDENTIAL"