Greetings, Word experts. I call again on those of you in the fields, if you'll pardon the pun. Here's my problem:

In a forthcoming proposal, the RFP issuer has stipulated that the TOC include both page number and total pages with each entry. Thus, for example:
A. Executive Summary .................1 of 60
B. Proposed Solution ....................5 of 60

(I have never seen this requirement before, but such is life.)

We have no problem numbering pages appropriately. At present, in the footers, we are using a Page field set to include the chapter number (a letter in this case, as in the example above), text "of", and then a Numpages field.
I also tried creating a bookmark at the final paragraph of the document and using a pageref field instead of the numpages one.

In neither case does the total page count display in the TOC. Perhaps you already knew that.

What we get is

A. Executive Summary ..........A-1

We can do without the included chapter designation, but not the "of 60".

I have spent an hour or so, both trying to insert additional fields into the TOC field (TOC is being generated by References/Custom Table of Contents) and trying to find a solution on the web, this forum included, to no avail. What I have seen is a number of references to workarounds for other problems involving numbering field conflicts, but my knowledge of fields is too limited to sort them out and apply specifics to this case. I understand that the relevant numbering is a section property, but the complexities elude me.

To be clear, therefore: This is a document that will have sections, but pages will be numbered consecutively, other than front matter, which gets the usual small Roman numerals, followed by pages with Arabic numbers starting with 1.

A member of our team says he once crafted a similar solution, but only toward the very end of production; it was not a permanent solution and could not be updated, was quite complicated and took him hours.

Short of removing hyperlinks and typing in the missing "of 60", or Rube Goldberging some strange concoction, is there a way to construct a TOC that will incorporate the now missing page total and be normally updatable?

Many thanks.