There is no complex procedure involved herein to calculate contribution once you have the weightage. That link just says that in the overall NIFTY movement what was the contribution of individual constituents of the index - May be plus and minus depending upon their today’s movement. So the formula will be -
Contribution1 = Weightage1 * (Percent Move of Constituent1)
Contribution2 = Weightage2 * (Percent Move of Constituent2)
…
…
ContributionN = WeightageN * (Percent Move of ConstituentN)
And if you do -
Contribution1+Contribution2 … ContributionN = Total Move of the Index Today.
In your example it is equivalent to -
HDFC(414.3) + KOTAK(142.8) … STOCKN(XYZ) = 728
Key is to find the weightage. Hope this helps.