My table structure is code c(8),cdate d(10),type c(1)...)

my index key is type+code+dtos(cdate)

Is it possible to use this index only seek for first two charactor are match
for example: type = 1,code = K0008,Cdate = 01/02/2001, sometime i will seek index for whole string but occasionaly I use it to seek only the first two character. Is that possible to use this index to seek instead of create another index to seek....

Sorry for my english. coding will be appreciated and thanks.