Hi Sank,
Ya it didn't work but thanks anyways...
I tried with putting ksh as the shell
#! /bin/ksh -p

and then using it like this
I=$(grep 'I.P. Address' /install/cfgdist/`uname -n`.cfg | cut -d : -f 2 | cut -d . -f 1-3 | sed s/" "//g)

and it worked

Thanks.
Regards,
Abhi