formula for list

group_name.txt

=IF(OR(LEFT(patient_name, 1)="A", LEFT(patient_name, 1)="B", LEFT(patient_name, 1)="C"), "ABC",
    IF(OR(LEFT(patient_name, 1)="D", LEFT(patient_name, 1)="E", LEFT(patient_name, 1)="F"), "DEF",
        IF(OR(LEFT(patient_name, 1)="G", LEFT(patient_name, 1)="H", LEFT(patient_name, 1)="I"), "GHI",
            IF(OR(LEFT(patient_name, 1)="J", LEFT(patient_name, 1)="K", LEFT(patient_name, 1)="L"), "JKL",
                IF(OR(LEFT(patient_name, 1)="M", LEFT(patient_name, 1)="N"), "MN",
                    IF(OR(LEFT(patient_name, 1)="O", LEFT(patient_name, 1)="P", LEFT(patient_name, 1)="Q"), "OPQ",
                        IF(OR(LEFT(patient_name, 1)="R", LEFT(patient_name, 1)="S"), "RS",
                            IF(OR(LEFT(patient_name, 1)="T", LEFT(patient_name, 1)="U", LEFT(patient_name, 1)="V"), "TUV",
                                IF(OR(LEFT(patient_name, 1)="W", LEFT(patient_name, 1)="X", LEFT(patient_name, 1)="Y", LEFT(patient_name, 1)="Z"), "WXYZ"
                                )
                            )
                        )
                    )
                )
            )
        )
    )
)