Try this.

C1 =IF(LEFT($A$1,1)&LEFT($B$1,1)="DD","a","d")
C2 =IF(LEFT($A$1,1)&LEFT($B$1,1)="DD","b","e")
C3 =IF(LEFT($A$1,1)&LEFT($B$1,1)="DD","c","f")

In D1 Data Validation Allow List =Data (Or select C1:C3) Ok

In A1 & B1 enter your text , I used Dog and Dog or Dog and Tog

The list in C1:C3 goes from a, b, c to d, e, f.

HTH
Regards,
Howard

"dkingston" wrote in message
...
i need to limit the available selections in a drop down list based on data
in
adjacent cells.
ex: if LEFT(A1,1)="D" and LEFT(B2,1)="D" then the list contains options a,
b
& c.
if LEFT(A1,1)="D" and LEFT(B2,1)="T" then list should have options d, e &
f.
i am using a data validation drop down list because i am not familiar with
visual basic or in using activeX control objects. i think i may need to
use a
list box.
please help and thanks in advance.