In Excel 2010 I am struggling to get the correct formula and really hope that any of you can help me. Please.

In sheet January I have values like below:
Week # Planned load. start Plan.load.start time Sales Document sold to party
1 02-01-2018 12:55 799999 123456
2 09-01-2018 9:01 799900 972585

Based on the week # I like the values to be copied to a sheet called wk01. I use the following formula:
=if(January!$A19=1;VLOOKUP(January!$A19;January!$A$19:$P$251;2;FALSE);"Empty"). If I use the same formula in sheet wk02 I end up with cells mentioning Empty because I copy and paste the formula to the sheet wk02. This to remain flexible.

I am looking for a formula that will copy the value from sheet January to wk01 (or wk02) but only if the value exists. Does such a formula exist?

Thanks a lot in advance for your help.
Marion