2 Added credits - apologies; forgot in last edit...
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Groovy - 5031 bytes

This is a tweak on carusocomputing's using string concatenation rather than list operations. (I would have commented on carusocomputing's but not enough rep to do so - sorry!)Groovy conversion of NumberKnot's solution in java:

{o='';itit.each{x=printf(int)"%02d",it-96;o+=(x<10?"0":""96)+x};o}

Example here using various options:

http://ideone.com/vd0dTX

Groovy - 50 bytes

This is a tweak on carusocomputing's using string concatenation rather than list operations. (I would have commented on carusocomputing's but not enough rep to do so - sorry!)

{o='';it.each{x=(int)it-96;o+=(x<10?"0":"")+x};o}

Example here using various options:

http://ideone.com/vd0dTX

Groovy - 31 bytes

Groovy conversion of NumberKnot's solution in java:

{it.each{printf("%02d",it-96)}}

Example here using various options:

http://ideone.com/vd0dTX

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source | link

Groovy - 50 bytes

This is a tweak on carusocomputing's using string concatenation rather than list operations. (I would have commented on carusocomputing's but not enough rep to do so - sorry!)

{o='';it.each{x=(int)it-96;o+=(x<10?"0":"")+x};o}

Example here using various options:

http://ideone.com/vd0dTX