Found IT !
I need to go in insert docvariable from the insert menu.
Then type {DocVariable MyVariable \* mergeforamt }

This will give you a error in the document ( variable not found)
But when the line "loWord.ActiveDocument.Variables("MyField").Value= MyField" is execute the field will be updated.

>I need to use Word to print a document with data from a .dbf.
>
>I use the OLE Automation with Word to do this.
>I like to use the word document variables to update the information in Word.
>
>I use this commands:
>

>loWord=CREATE('Word.Application')
>loWord.ActiveDocument.Variables("MyField").Value=   MyField
>

>
>But I do not remember how to create the document.variables in Word.
>Right now ( on client site) I do not have the VBA documentation.
>Any one remembers how to do this?