TSQL- csv for a column and not for the rest

Question

i need to get csv from a column but the minimum value from the rest of the columns (or any value because they are same for a group). As an example;

I have the following

Answer 1

Sample Data

DECLARE @Table1  TABLE 
    (COL1 varchar(3), COL2 int, COL3 int, COL4 varchar(6))
;

INSERT INTO @Table1
    (COL1, COL2, COL3, COL4)
VALUES
    ('ABC', 10, 35, 'GROUP1'),
    ('AQW', 10, 35, 'GROUP1'),
    ('VBN', 10, 35, 'GROUP1'),
    ('HJK', 10, 35, 'GROUP1'),
    ('DFV', 30, 25, 'GROUP2'),
    ('HYT', 30, 25, 'GROUP2'),
    ('DET', 30, 25, 'GROUP2')
;

Script :

SELECT   COL1 = STUFF(
             (SELECT ',' + COL1 
              FROM @Table1 t1
              WHERE t1.COL2 = t2.COL2
              FOR XML PATH (''))
             , 1, 1, ''),COL2, COL3, COL4 from @Table1 t2
group by COL2, COL3, COL4;