Set count of instances of certain building type necessary to be owned to fulfill Prereq

Please include a way to set the prerequisite in a way that requires the player in question to own a certain number of buildings of a type in order to have access to the building option in question. For example:

[XAMPLEGUY]
Name=Example unit
Prerequisite=GAPILE,GATECH
PrerequisiteNum=5,2

would mean that the Example unit becomes available only when the player has at least 5 GAPILEs and 2 GATECHs.

or even a PrerequisiteMinNum and MaxNum?