The problem is because MS Word is mistakenly trying to format your numbers as they should be formated when there is hebrew text around it. (Right-To-Left). So to fix it we need to tell MS Word to keep it Left-To-Right. Unfortunately MS Word doesn't have a direct way of changing this setting. So in order to get to this setting follow
1. In the report screen click on the menu "Options" and select "Correct Right-to-Left Labels".
2. Click "Create" on any mail merge.
3. A dialog will pop up and de-select the option "Open as Right-to-left document".