Remove Text from String Converting Numbers to Integer

How do I remove text from a string "MIC-CT-001", and convert the remaining numbers as an Integer, where I can add 1 to the numeric, convert back to a string and push back to the Spreadsheet?

Public Function UniqueID()

Call SetVariables

DIM LastID as String
DIM LastNumber as Integer
DIM NextNumber as Integer
DIM NextID as Integer

LastID = xTracker.Range("B" & tRow).Value

'==========================
'Remove text from string
'==========================

NextNumber = LastNumber+1
NextID = ("MIC-CT-" & NextNumber)

End Function

Unfortunately this is as far as I can go without removing the text from the string and converting it to an Integer.