sql querry

Question

testcode           eligibility(subjects)
100                8,26,36,40
101                18,56,87,10
102                38,28,46,11
103                48,128,58,68

this is my sample data

 my question is
 i want to retrieve the data from the above table depending on user requmnt
if user choose the subject no 8 then he had to get only 100 row not only remaining rows
if user choose the subject no 28 then user to get only 102 row not the 102 & 103
please help me how to write the command . please help me

 thanks in advance