Joins and the BOLHeader file

How does one join the BOLHead file to the ShipHead file for a Report
Builder report?

The BOLHEad->BOLNum field is numeric, and the corresponding field
(ShipHead->ShipLog) is a character field. Unfortunately, the Str()
and Val() functions, while available in Report Builder, are
not 'Server Evaluatable' and therefore are not available for use in a
join.

Alternatively, how does one export the appropriate fields to use a
Crystal report? Are there any other alternatives?

One report that is being requested is to show Freight Charges for
Shipments which have yet to be invoiced. It is simple to sort on the
ShipLog field, but I can't get the Freight Charges information out of
the BOLHead file.

Thanks in advance,

Chris Park
(masquarading as Steve Ashton for lack of a local email address)