TCL script : need help

Dear Sir,

I am Begineer to TCL scripting. need small help

actually i am developing a small script i.e 

lets say i have few components with naming like COMPNAME_MATNAME_Txx.  this script will read COMPNAME & and it will create a PSHELL property with thickness (xx) with same name. and also it will read MATNAME and it will create material with same name.

 

Q) i want split the original compname & matname and assign to some variable like this :    set thickness [string trimleft [lindex [split $comp_name _] end] t]

how to do this one?

I have done with simple commands like (string range).please refer below picture

 

 

Thank you,

Regards,

Gopi

<?xml version="1.0" encoding="UTF-8"?>