How to handle errors caused by Mailmerge in VB

[Bindhu]

We have a VB program which opens word documents and data
source and performs mailmerge programmatically.
Whenever there is a problem with mailmerge (eg: some
mergefields are missing) the word session hangs.
It pop-ups some dialogs, like "Record and header
delimiter" or "invalid merge field". These dialogs require
manual intervention but, programmatically it is difficult
to supress these dialogs, the reason being there are
multiple scenarios or worse still the WORD session itself
is hidden.
Is there a way to handle such scenario's using VB?
Any suggestions will be greatly appreciated.

Thanks
Bindhu