Insert dot into string MS Access

I have an Access table with about 90K records.   The field I need to change has a varying number of characters, between 3 and 7.   I need help for an Access update query that would insert a dot between 3rd and 4th characters.   Preferably no dot if the field has just 3 characters.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Rey Obrero (Capricorn1)Commented:
create a backup of your table first
run this update query

update tableName
set [fieldName]= left([fieldName],3) & "." & mid([fieldname],4)
where len([fieldName]>3
Rey Obrero (Capricorn1)Commented:
oops, missing ")" before >

update tableName
set [fieldName]= left([fieldName],3) & "." & mid([fieldname],4)
where len([fieldName]) >3

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
rrutland88Author Commented:
Thank you worked perfectly!   You are brilliant and I appreciate the fast expert response very much!
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Access

From novice to tech pro — start learning today.