OT: need advice with regex

[Tiemo Hollmann TB]

Hi,

I want to replace a string with an opening and closing square bracket and
any sign in between with three question marks, like this

put replacetext(tFilter,"[?]","???") into tFilter

I tried to escape the square brackets like this:

put replacetext(tFilter,"\[?\]","???") into tFilter

and get as a result in tFilter only the second bracket replaced.

What am I doing wrong? Thank you

Tiemo