changing database source in data environment for datareport,

hi, im using datareport in my program and the program has 4 databases that has the same tables and queries. the user of this program choose 1 database according to its assigned location and each of the databases has a datareport. the databases were changing because these databases acts like user accounts. Actually these database were warehouses and each warehouses has a manager in-charge.

I have done the 1st database to the data environment to show the datareport.
What should I do to do it the same to the other 3 databases?
is there a code for changing the database source in the data environment?

these is the flow of the program. when the 1st user log-in on his account, the 1st database will be chosen and he will print its datareport, the 2nd user log in on his account, the 2nd database will be chosen and he will print its datareport, and it will be the same with the 3rd and the 4th...

do anybody has an idea about my situation?
thanks in advance...