You could create a hyperling field with a FILLIN field nested within, thus:
To do this:
• Type into the document, then press Enter. Word will create the hyperlink with the full address displayed.
• Right-click on the hyperlink and choose 'Edit Hyperlink', to give the hyperlink a name that tells the user what to do (e.g. 'Select then press F9 to update')
• Press Alt-F9 to expose the field code, which will look like:
Then, before the final ", insert a FILLIN field coded along the lines of:
{FILLIN "QR String"}
Then press Alt-F9 again to toggle the field code display off.

From now on, if you select the hyperlink and press F9, as per the hyperlink display text, you'll get a pop-up asking for the QR string. If you input that, then click on the hyperlink display text, you'll be taken to the page displaying that QR code.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]