Installable Custom Files

Hi,

I’m setting up a installable patch and have a question about custom files.
I need to modify just one core file:

/modules/iCals/iCal.php

If I create a manifest file to copy the modified iCal.php to

/custom/modules/iCals/iCal.php

and install the patch… Will sugar automatically know to use the Custom version instead ?
If not, how to I go about tell Sugar to use the custom version.

Thanks

It will automatically know to use the Custom version.