formulae for icon set conditional formatting

[kcmuppet]

In colmun S I've got cells with values likes these in them:

98 (+2)
103 (-8)
112 (0)


I want to use conditional formatting to choose from a set of 3 icons based on the number on the left,

>109 = green icon
100-109 = yellow icon
<100 = red icon


Against the top / green icon I set Type to 'Formula', and in valyue I put
=value(left(S2,find(" ",s2)))>109

Against the middle / yellow icon I set Type to 'Formula', and in valyue I put
=AND(VALUE(LEFT(S2,FIND(" ",S2)))>=100,VALUE(LEFT(S2,FIND(" ",S2)))<=109)

...but Excel said "You cannot use relative references..."

Anybody know how to work around this?

Many thanks