Q:

VBA Excel - Update Cell value based on other cell value

I am trying to write a formula in a  Range of cells based on other range cells values from another worksheet. The formula is shown below:
ActiveSheet.Range("G14:G43").Formula = "=Worksheets("1ºperíodo").Range("V14:V43").Value"

But the code doesn't work and I get a syntax error. That must be related with the strings but I don't know how to fix it. 
The value  at V14 must be equal to the value at G14 until the last cell, i.e., the value at G14 equals the value at V43. Besides the syntax error   is the formula correct based on what I expect to have?

A:

"=Worksheets("1ºperíodo").Range("V14:V43").Value"

is not a formula.  It is a value.
If you only want the static values then just assign the values:
ActiveSheet.Range("G14:G43").Value = Worksheets("1ºperíodo").Range("V14:V43").Value

If you want a live formula you need to pull vba from the string and use the .Address function:
ActiveSheet.Range("G14:G43").Formula = "=" & Worksheets("1ºperíodo").Range("V14").Address(0,0,,1)

But the above can be simplified to:
ActiveSheet.Range("G14:G43").Formula = "='1ºperíodo'!V14"

With the formula, we only need to refer to the first cell with a relative reference and vba will make the changes to each row.

