Logical partition turns into Principal

Hello all,

I got a big problem with my data.
I have an ATA disk that was partitionned into two, one Principal and one logical.
In the logical partition, I had a drive on which I had a lot of Data.
When I wanted to install winXP onto the principal partition, instead of hiting enter to install on it, I first hit D to delete the partition in order to install on a “clean” drive.
Little did I know that when a Principal partition of a disk is deleted, the logical partition is automatically made principal and now I do not see any of my data!
I am convinced that they are still there because I didn’t format it when I realize my error.
My question is : Is there anyway to recover my data, and if yes, anyone care to help me?

Thank you in advance.