microsoft jet 4.0 oledb provider

hi,

i  need to use,following provider ,

native oledb\microsoft jet 4.0 oledb provider.

now here in connection string, i have date source = c:\users:\.txt

i need to make this dynamic,like need to give variable name,so whatever file comes ,it wil pick it up

if i put data source -user::file1

it give sme error not valid file format.

i cannot use connection string,because it involves other things

please help me