I think the Tab char should be $I
So
="*" & Fields!MtlQueueSeq & "$I*"
Or
="*" & Fields!Calc_BCMTLQueueSeq.Replace("*","") & "$I*"
// if Fields!MtlQueueSeq didn't exist
But whether it is $I or %I, may depend on the configuration of the scanner
To verify what the the SSRS’s rendered output is, Scan the barcode it generates into a word doc. I did a test of for MtlQueueSeq = 10, encoded with the various “control char sequences” (%I and $I)

So my scanner interprets the $ and % as actual characters, and not an escape sequnce for special character.