Finding square brackets around digit ranges (aka Wikipedia footnotes)

Situation: Running Find on rich text.

Goal: I want to Find Wikipedia footnotes (e.g., “[34]”, “[2]”) and Replace them with nothing.

Problem: Normal Find can find the “[” character, but I need a digit wildcard, and the DevonThink help recommends the digit regex [0-9].

The solution would be to Replace All with \[[0-9]\] and then \[[0-9][0-9]\]. That would get them all.

But [ and ] are not Findable when “Enable Operators & Wildcards” is selected.

Moreover, [0-9] doesn’t work, either!

How to find Wikipedia footnotes, then?

DEVONthink doesn’t support this, the only options are either a custom script or a third-party app.