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:

B1: 
=IF(EXACT(UPPER(LEFT(A1;3));LEFT(A1;3))*(MIN(FIND({1\2\3\4\5\6\7\8\9\0};A1&1234567890))=4);1;NA())
copied down

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:

B1: 
=IF(EXACT(UPPER(LEFT(A1,3)),LEFT(A1,3))*(MIN(FIND({1,2,3,4,5,6,7,8,9,0},A1&1234567890))=4),1,NA())
copied down

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.

Option Explicit
Sub TEST()
    Dim CharPos     As Long, _
        RowCount    As Long, _
        TestRow     As Long
    
    RowCount = Cells(Rows.Count, "A").End(xlUp).Row
    
    For TestRow = RowCount To 1 Step -1
        
        CharPos = 0
        Do
            CharPos = CharPos + 1
        Loop While (CharPos < Len(Range("A" & TestRow).Value) And (Asc(Mid(Range("A" & TestRow).Value, CharPos, 1)) - 91 > 0))
        If CharPos = Len(Range("A" & TestRow).Value) Then
            'Debug.Print Range("A" & TestRow).Value
            Range("A" & TestRow).EntireRow.Delete
        End If
    Next TestRow
End Sub