Script to get OS install date

I have a script to get OS install date. It uses this command line to output data to text file:

systeminfo|find /i "original install date" > C:\OSInstall.txt

Then i take that and place it in a custom kaseya column. The command line outputs like this "Original Install Date:      6/3/2013, 6:56:22pm"

Anyone know how i can remove the text "Original Install Date:       "