Centering of Dummy Coefficients

["kevin@themidwaygroup.com" <kevin.themidwaygroup@verizon.net>]

Hello,
        Is there a way to "center" the design variables when using the 
"treatments"
contrast with logistic regression? This is an example of what I would like
to do:
Default in SPLUS:
Group Levels: OTM4,OTM3,OTM2,OTM1,ATM,ITM1,ITM2,ITM3,ITM4
Treatment Matrix:
        OTM3 OTM2 OTM1 ITM1 ATM  ITM2 ITM3 ITM4
OTM4    0    0    0    0    0    0    0    0
OTM3    1    0    0    0    0    0    0    0
OTM2    0    1    0    0    0    0    0    0
OTM1    0    0    1    0    0    0    0    0
ATM     0    0    0    1    0    0    0    0
ITM1    0    0    0    0    1    0    0    0
ITM2    0    0    0    0    0    1    0    0
ITM3    0    0    0    0    0    0    1    0
ITM4    0    0    0    0    0    0    0    1

I would like the design variables to be coded as follows:

        OTM3 OTM2 OTM1 ITM1 ATM  ITM2 ITM3 ITM4
OTM4    1    0    0    0    0    0    0    0
OTM3    0    1    0    0    0    0    0    0
OTM2    0    0    1    0    0    0    0    0
OTM1    0    0    0    1    0    0    0    0
ATM     0    0    0    0    0    0    0    0
ITM1    0    0    0    0    1    0    0    0
ITM2    0    0    0    0    0    1    0    0
ITM3    0    0    0    0    0    0    1    0
ITM4    0    0    0    0    0    0    0    1

I am using SPLUS 6 w/windows


Thank you in advance,

Kevin P. Scherer