querry..

hi list,
 

how can i select two columns from a
table based on condition that they are selected in specified combinations.
 

let me..
table 1 has 2 columns col1, col2.
both cols have values , say, alphabets. a,b,c,d,e,f,... i'want to select like
 

FOR VALUE OF COL1 IN A,  col2
must fetch only between A-E
for value of col1 in B, col2 must
be between A-X

--


 and so on..

 

i want to define this combination, 
so i should get only these pair of values.


 

any suggestions.
thanks.


 

saurabh