You would have to create your map templates from the point of view of S1000D Information Codes and Schemas, the most used would be description and procedure. However, MSWord is terrible due to the inconsistent styles used, and you are trying to map format to meaningful markup. It may pay to sanitize documents first into something stylistically consistent which you can control.
In a typical document's subject matter, say a manual, you will find it could easily be broken down into many different Data Modules by Information Code. Be aware there will also be backfill required. Information will be missing which is required in the S1000D Data Modules. This missing and required information you will have to supply.
Overall, unless you understand S1000D really well you may find it a daunting but not impossible task. It sounds like you may be jumping into the deep end without defining business rules or obtaining a BREX. These are a very important part of S1000D, particularly for data exchange.
Be aware that there may be government trade restrictions which impact off-shore content conversions. Some information simply cannot be exported.