formula macro

[john_cash]

Hi to all.
In range L4:L5000 there is this formula

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but it slows down the file a lot.
is it possible to create this macro?

IF k4 >1 then L4 = TEXT(K4,"0000-00-00")*1

must work from L4: L5000
john

[john_cash]

I did this:

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it is possible to do

IF k4 >1 then L4 =IF(ISERROR( TEXT(RC[-1],""00-00-00"")*1),"""", TEXT(RC[-1],""00-00-00"")*1)"