Drop-down list formula based on first 3 characters of variable input in a different cell.

Can anyone help defining a formula for data validation for the following:

In column C, input will either begin with PR7, WS8 or HW9. The range for this input can be anywhere from:
PR700000 to PR799999, WS800000 to WS899999 and HW900000 to HW999999.

I have 3 drop-lists I want to use in column H based on the first 3 character-input in column C .

PR7xxxxx would drop down List1 in column H
WS8xxxxx would drop down List2 in column H
HW9xxxxx would drop down list3 in column H

i.e. PR745862 or PR711145 as input in column C would show drop-down list "List1" for column H.
i.e. WS850006 or WS899555 as input in column C would show drop-down list "List2" for column H.
i.e. HW967891 or HW945000 as input in column C would show drop-down list "List3" for column H.

I've looked, read, watched countless articles for data validation, but all are based on defined input rather than variable input.

Any help would be appreciated.

Cheers, ScottyDo

I need to change a cell to a drop down list, can somebody help me??

This formula did not work for me. Could be that I'm doing this in Norwegian but I've translated it into what I believe is the correct Norwegian spelling.

You wrote =INDIRECT(LEFT(A1,3)&"_") and I translated it into =INDIREKTE(VENSTRE(A1,3)&"_")

On my worksheet called "List", I have 3 columns that hold the lists I need.
The 1st column is named PR7_, 2nd is WS8_ and 3rd is HW9_ as you suggested.

On my sheet1, I highlight the H column cells where I want the drop-down list, choose data validating, choose List and then enter the above formula (in Norwegian) that you gave me.
I get an error msg saying this is not a formula. (same error msg if I use the English version)

Thx NBVC, you are right. We use a semi-colon instead of the comma and the formula works perfect for what I need. Thank you for your help.