Hey Pico,

If you have Adobe Standard (not reader) then I'm pretty sure you can just invoke the PrintOut method via code and change the ActivePrinter to Adobe PDF and it will automatically bring up the saveAs dialogue box. Haven't tested, but I've done that with other programs (CorelDraw, for instance). But make sure you leave PrToFileName blank so you can manually write in the name.

From the help files:
expression.PrintOut(From, To, Copies, Preview, ActivePrinter, PrintToFile, Collate, PrToFileName)

 expression Required. An expression that returns an object in the Applies To list.

From Optional Variant. The number of the page at which to start printing. If this argument is omitted, printing starts at the beginning.

To Optional Variant. The number of the last page to print. If this argument is omitted, printing ends with the last page.

Copies Optional Variant. The number of copies to print. If this argument is omitted, one copy is printed.

Preview Optional Variant. True to have Microsoft Excel invoke print preview before printing the object. False (or omitted) to print the object immediately.

ActivePrinter Optional Variant. Sets the name of the active printer.

PrintToFile Optional Variant. True to print to a file. If PrToFileName is not specified, Microsoft Excel prompts the user to enter the name of the output file.

Collate Optional Variant. True to collate multiple copies.

PrToFileName Optional Variant. If PrintToFile is set to True, this argument specifies the name of the file you want to print to.
Hope this helps