Normally speaking, I woudl recommend that you install DP 7 on your existing cell manager, and do your upgrade. However, a check of the DP 7 support matrix shows no support for W2003 32-bit (only 64-bit)
However, DP 6.2 is supported on 32-bit, Therefore, this should be a multi-step operation. Get teh 6.2 Installatio bits
https://h20575.www2.hp.com/evalportal/displayProductsList.do?prdcenter=HPSS_DM&lang=en&cc=US&hpappid=PDAPI_EVAL_PRO2
INstall DP 6.2 on your existing system according to the Installation and licensing Guide for 6.2
http://support.openview.hp.com/selfsolve/document/KM1120153?searchIdentifier=3347a12%3a145196f117b%3a6cec&resultType=document&documentURL=KM1120153&resultsURL=%2fselfsolve%2fmanuals&allowReturn=true&searchString=&searchKey=
I did not see any kind of IDB conversion involved in this upgrade. I recommend that, at this time, you install the DP 6.21 patch bundle, available from
http://support.openview.hp.com/selfsolve/document/KM1307025?searchIdentifier=3347a12%3a145196f117b%3a6e9c&resultType=document&documentURL=KM1307025&resultsURL=%2fselfsolve%2fpatches&allowReturn=true&searchString=&searchKey=
Run a few backups to be sure that the upgrade went successfully, then, install DP 6.2 on your new call manager. Run a few local backups (on the cell manager system), then upgrade it to DP 7
http://support.openview.hp.com/selfsolve/document/KM1363249?searchIdentifier=3347a12%3a145196f117b%3a6dde&resultType=document&documentURL=KM1363249&resultsURL=%2fselfsolve%2fmanuals&allowReturn=true&searchString=&searchKey=
It appears that there is no IDB conversion for this version either. I advise that, at this time, you upgrade to the DP 7.03 patch bundle
http://support.openview.hp.com/selfsolve/document/KM00618388?searchIdentifier=3347a12%3a145196f117b%3a6f36&resultType=document&documentURL=KM00618388&resultsURL=%2fselfsolve%2fpatches&allowReturn=true&searchString=&searchKey=2014-04-01+08%3a27%3a42
Now, having said all of this, there is a direct upgrade path from 6.11 to 7.0. The problem is that you are changing OS-versions at the same time
You may want to backup your 6.11 IDB onto tape, install DP 7.0 fresh on the new cell manager, create a temporary device to IMport that tape, and do the IDB restore
Once you have DP 7 installed, you can use the Client context to upgrade your clients to 7.0, if the Cell Manager hostname is not changing, thsi should be an easy task
One thing to remember, always plan as if the upgrade will fail. Make copies of the COnfiguration files
Program Files -> Omniback -> Config -> Server
and of the DP IDB
Program Files -> Omniback -> db40
so that, if things don't go well, you can go back to the previous version with a minimum of downtime