retrieving product additional fields in custom shipping

[bookman]

I have a custom shipping add cgi in which I requre the values of the product field 1 for each item. In the help docs at

http://www.shopsite.com/help/9.0/en-US/ ... lates.html

there is a reference to

pXapi_fieldF=bbbbb… Information from up to ten extra Product Fields may be included, depending on the Extra Product Field settings and the Shipping Add on configuration.

However I cannot get this to work. I have checkmarked the item Product Field 1 in the Custom Shipping configuration and am searching for $name eq "p1api_fieldF"

any help appreciated.

tia
bob