Excel formula help

[lillyg424]

Hi, 

I am having trouble in my excel spreadsheet trying to replace data in one column with an if statement. I want to be able to replace the date listed in column D with the date listed in column L, ONLY IF column K is equal to RS (rescheduled). 

I have been using the equation =IF(K12=Totals!$N$11, Dereck!L12,"") in an entirely new column, but was hoping to be able to keep it in column D, rather than a new one. 

If anyone has any solutions please help!

[#2]

Assuming initially you put dates in D manually and want to change them if some condition met, otherwise keep unchanged - that's only with macro.

[#3]

Thank you that helped! I created the macro, is there anyway that the macro can be applied automatically when column K is equal to RS? Where column D would change on it's own rather than me having to do it manually each time?