vb.net - regex for replacing only double apostrophes -

vb.net - regex for replacing only double apostrophes -

i searched , not find answer.

i need replace non-double apostrophes single apostrophe.

abc'def''ghi'x -> abc''def''hgi''x ''abc'def' -> ''abc''def'' 'abc''def -> ''abc''def

i dont want this:

abc''def -> abc''''def

all of solutions i've seen fail if apostrophe @ start or @ end. utilize vbnet. help welcome. regex or other form of code appreciated.

a simple regex (?<!')'(?!')

regex vb.net str-replace