delete row based on criteria

hello,
I have some datas :
DRB1obed
GRC2vecera
ranajky
olovrant

and I need this : If first 3 characters are capital letter followed by number then do nothing, but if not then delete whole row ... it means after macro (or function?) result should be :
DRB1obed
GRC2vecera

thanks for any help !

You could use VBA for sure but on the off chance it's a one off you could equally just insert a helper calc, eg:

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once the above is in place:

-- Highlight column B -> F5 -> Special -> Formulas: uncheck all but Errors -> OK
-- via Home Tab on Ribbon -> Delete Sheet Rows
-- finally delete column B to remove legacy formulae.

In my locale it would be:

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see the attached - it should auto translate to your own settings upon opening - from which you can copy the formula (to your file).

The code below worked for the small sample data provided.

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