function GetAttachmentStringValue(Index: Integer; const Key: WString): WString;
| Index | Integer. Zero-based index of the document-level attachment. |
| Key | WString. Name of the file-specification dictionary entry. |
| Result | WString. The stored value, or an empty string when the key is absent or holds no text. |
Reads private metadata a producer stored alongside an embedded file - a source path, a content hash, a workflow marker - without going through the raw document structure
An empty result covers both a missing key and an empty value; use AttachmentHasKey when the difference matters
The standard entries have their own properties: AttachmentName, AttachmentType, and AttachmentDescription