If you want to access the db2clp from cygwin on windows, this post will be useful for you.

#install the cygwin (can follow the guide from cygwin)

#install the puttycyg (download the puttycyg-20101029.zip from google)

#set the db2 environment in cygwin environment home user login scripts, e.g.: ~/.bash_profile

export DB2CLP=**`ps -ef | grep “/cygdrive/c/dev/puttycyg-20101029/cthelper” | awk ‘{print $2}’`**
export LANG=en_US.utf8

#enjoy