I need to loop through the returned recordset and look at just the NUMBERS past the last R

Setup:
I have a variable that houses a precalculated value like:
glb_cboRebate_Lookup = SLS-000118-MAIN-A1-5-R5
also a precalcuated string:
glb_string =  SLS-000118-MAIN-A1-5-R

I have an sql i'm running.

' checking to see if new glb_cboRebate_Lookup  exists in table already , so we do create an error with a duplicate.
Set R = CurrentDb.OpenRecordset("SELECT * FROM [Program_Header] WHERE [Rebate_ID] LIKE '" & glb_cboRebate_Lookup & "' ", dbOpenDynaset, dbSeeChanges)
' WHAT HAPPENS IF IT CANT FIND ID
record_count = R.RecordCount

If record_count > 0 Then
   MsgBox "ID Already Exists!", vbCritical, "Search ID"
   Exit Sub
End If

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glb_cboRebate_Lookup -  looks like  SLS-000118-MAIN-A1-5-R5



So now i have to run a second sql that does a wilcard for just the following: variable
glb_cboRebate_LookupWild =  SLS-000118-MAIN-A1-5-R

' checking for wildcard on string
Set R = CurrentDb.OpenRecordset("SELECT * FROM [Program_Header] WHERE [Rebate_ID] LIKE '" & glb_cboRebate_LookupWild & "*' ", dbOpenDynaset, dbSeeChanges)

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The return will look like the following:
Rebate_ID
SLS-000118-MAIN-A1-5-R1
SLS-000118-MAIN-A1-5-R10
SLS-000118-MAIN-A1-5-R4
SLS-000118-MAIN-A1-5-R5
SLS-000118-MAIN-A1-5-R6
SLS-000118-MAIN-A1-5-R7
SLS-000118-MAIN-A1-5-R8
SLS-000118-MAIN-A1-5-R9

What I need:
I need to loop through the returned recordset and look at just the NUMBERS past the last  R  -  "SLS-000118-MAIN-A1-5-R"
CREATE AN ARRAY of the numbers:
in this case  (1,10,4,5,6,7,8,9)
Get the max value in that array , in this case  10


jj = array(max_Numeric)
and then

take that numeric and add it to
glb_string =   glb_string & max_Numeric)

So the new Number will be
 SLS-000118-MAIN-A1-5-R11



I hope this makes sense:
Sorry for the long explanation
fordraiders