Using variables with text values

Greetings All,

I need help with a solution. I used the GetName javascript and change to Student ID to get the information from LMS. This works. I am trying to create a elearning  where navigation is based on a text value(Student ID). But now I want to have a variable that reads that information and based on the first character jumps to a particular slide.  Is there a way to create a variable that can do this. Or is there a way to only retrieve the 1st or 1st&2nd character of the Student ID only from the LMS. (like 1st initial of name vs. whole name). The end product will be learner is sent to a particular slide based on this information.

Example:

Student ID = A1XYZ45... reads A or A1 and jumps to slide 4

Student ID = B1XYZ45.. reads B or B1 and jumps to slide 10

(NOTE: trying to give learner information based on there location, cannot get LocationID from LMS using script, but 1st digit of StudentID is their location also).

Thanks in Advance!